Chapter 2. How to Get There: The Global Justice Fund 2026-2100

To reconcile equality, prosperity, and planetary habitability, the Global Justice Platform must address several key challenges. In particular, the “Sustainable Convergence” trajectory described in Chapter 1 requires substantial resources to finance expenditures on education, health and climate infrastructure. The Global Justice Fund (GJF) is the centerpiece of the Global Justice Platform and the key institution responsible for addressing these challenges. It is designed as a new international institution dedicated to global socioeconomic convergence and to financing sustainable development and the energy transition at the global scale. Its key objective is to ensure equitable development opportunities for all countries while limiting global warming to below 2°C and sustaining political support from low- and middle-income classes in both the North and the South.
 
We first describe the general architecture of the Global Justice Fund (Chap. 2.1). We then proceed with country dividends and their impact on access to education and health (Chap. 2.2), the World Sovereign Fund and the new balance between public and private wealth (Chap. 2.3), and the global wealth and income taxes and their impact on inequality (Chap. 2.4-2.6). Finally, we show that a vast majority of the population – about 95-98% in the Global South and 85-95% in the Global North – benefits from rising monetary incomes in our benchmark trajectory, but with large variations across countries and scenarios, potentially implying fierce opposition from beyond just the ultra-rich (Chap. 2.7) [1]This Chapter aims to synthetize some of the material that is presented in a more detailed manner in Bothe et al (2026). We refer all interested readers to this work and to the online replication package.

Figure 2.1 describes the overall organization of the Global Justice Fund. In short, the GJF is responsible for raising adequate revenues (via global wealth and income taxation), managing a World Sovereign Fund (made up of previously accumulated tax revenues) and distributing country dividends (allocated to each country on an equal per-capita basis and used to finance climate investment, education and health expenditures).

In our benchmark scenario, total GJF revenues and expenses represent around 8-10% of world GDP on average over the 2026-2060 period, with higher figures for the first decade (14%) and lower values for the second half of the century (5%). This represents far more resources than the total combined resources currently allocated to development aid or international organizations (less than 0.4% of world GDP) (Figure 2.2) [2]World GDP is projected to be about 140 trillion Euros (PPP) in 2026, which means that GJF revenues and expenses are scheduled to be of the order of 12-14 trillion Euros in the coming years. Note however that all nominal amounts are quickly changing, due both to price inflation and real growth, so it is highly preferable to express all amounts as fractions of world GDP or other relevant denominators, as we do in the present report. All series expressed in money amounts are available online. While this may seem large, the point is that it includes not only climate investment needs (about 3-4% of world GDP per year in the coming decades) but also new education and health expenditure aimed at fostering global convergence. As we show below, this still falls short of what equal access to education and health would require.

The overall structure of GJF revenues and expenses, and their projected evolution over the 2026-2100 period, are described in Table 2.1 and Figures 2.3a-2.3b. We summarize the broad contours here, starting with revenues and then moving to expenses (each of these elements are laid out in greater detail in subsequent sections). GJF revenues come from a global wealth tax, a global income tax, and the investment income coming from a World Sovereign Fund (WSF), which itself is accumulated out of previous tax revenues. The global wealth and income taxes come in addition to national tax systems and target the top of the global distribution (typically over 10-20 times the world average wealth and income levels; around 1% of the world population).

Several points are worth stressing about GJF revenues. First, wealth tax revenues play a crucial role during the 2026-2035 period (as much as 8-10% of world GDP in annual revenue on average in 2026-2029, and 4-6% per year in 2030-2035) and then become gradually less important over time. In effect, the global wealth tax generates substantial payments from top wealth holders – especially decamillionaires, centimillionaires, and billionaires – between 2026 and 2035, and these payments are primarily used to accumulate assets in the WSF. In turn, these assets generate investment income, which gradually becomes more important than tax revenues. By 2050, wealth tax revenues account for 1.0% of world GDP, income tax revenues for 0.9%, and investment income for 5.8%. By 2100, all GJF revenues come from investment income (4.2% of world GDP) (Figure 2.3a). We will return below in more detail to the projected structure of wealth tax rates and tax payments.

It is worth stressing that projected revenues from the global income tax also play an important role but are significantly smaller than those from the global wealth tax, especially in the early period of the GJF. Between 2026 and 2035, income tax revenues account for an average of 4.0% of world GDP per year, compared with 6.8% for the wealth tax and 3.3% for investment income. Between 2036 and 2060, both the global income tax and the global wealth tax raise 1.6% of world GDP per year, compared with 5.5% from investment income. Over the 2060-2100 period, tax revenues in general become almost negligible (0.1% of world GDP per year for the wealth tax, 0.4% for the income tax) compared with investment income (4.8%) (Table 2.1).
 
There are several reasons why the Global Justice Platform places greater emphasis on the wealth tax than on the income tax. First, the rise in top wealth concentration has been particularly spectacular in recent decades, [3]See the World Inequality Reports 2018, 2022 and 2026 coordinated by Alvaredo et al (2018) and Chancel et al (2022, 2026) (all available on wid.world) and governments have done very little to address it. One standard explanation is that national governments – who were the main actors behind the liberalization of capital flows [4]See Abdelal (2007) – now find it difficult to tax highly mobile top-wealth owners on their own. The Global Justice Fund, by relying on a common global wealth tax, offers an opportunity to circumvent these difficulties. In comparison, national governments face relatively fewer difficulties in redistributing income (via taxation and other tools like labour market rules), at least up to a point, so it is logical to rely more on the national level for income-related policies and more on the global level for wealth-related policies [5]It must be noted, however, that national governments should in our view develop progressive wealth and income taxes on their own, in addition to the global taxes. See Chapter 2 on national policies. Next, given that one of the key objectives is to build up a substantial sovereign fund and transform property structures, it makes sense to rely more heavily on a global wealth tax than on a global income tax, especially at the beginning of the asset accumulation process. 
 
Turning to GJF expenses, they take two forms: country dividends (allocated to each country on an equal per-capita basis and used to finance climate investment, education, and health expenditure) and gross investment flows accumulated in the WSF. During the early years of the GJF (2026-2035), most of the revenues collected through global wealth and income taxes are devoted to investment flows and the buildup of the sovereign fund (Figure 2.3b). The objective is for the size of the WSF to reach about 60% of world GDP in assets by 2035 (about 10% of the world capital stock) and then stabilise around that level. Starting in 2050, WSF investment flows are set to equal exactly one-tenth of the aggregate world investment flows projected in our benchmark “Sustainable Convergence” scenario, so that, by construction, WSF assets stabilise at about 10% of the world capital stock (more on this below) [6]Aggregate gross investment flows are projected to rise from 27% of world GDP in 2025 to 31% in 2050 (reflecting the increased investment in climate and infrastructures and the accelerated convergence process), and then to decline to 20% by 2100 (reflecting the decline in aggregate economic growth, especially the zero or slightly negative population growth). Aggregate capital stock is projected to rise from 521% of world GDP in 2025 to 600% by 2100. See Chancel et al (2026), Figures 10-11.

In effect, over the 2026-2035 period, nearly two-thirds of GJF expenses (8.4% of world GDP) would be directed towards building up the WSF asset base, while country dividends start at relatively low levels and rise only gradually. Subsequently, over the next 25 years (2036-2060), once the WSF base has been built up, more fiscal space would be available for country dividends, which would account for two-thirds of total GJF expenses (5.7% of world GDP). Finally, over the 2060-2100 period, country dividends and flows into the WSF would each account for about half of GJF expenses (2.7% of world GDP) (Table 2.1).

The Global Justice Fund allocates country dividends to finance climate investments, as well as education and health expenditures. Country dividends are assumed to be distributed on an equal-per-capita basis, so that the geographical distribution of country dividends, by construction, follows the distribution of population across regions. In our benchmark scenario, country dividends represent 4.1% of world GDP on average over the 2026-2100 period, including 5.7% on average in 2036-2060 (and up to 8-9% around 2030-2040, when a big push in new climate investment and education and health expenditure is particularly needed) and 2.8% in 2061-2100 (when global socioeconomic convergence is already well advanced) (Table 2.1).

Given that country dividends are distributed on an equal per-capita basis, they represent a smaller fraction of GDP in rich countries than in poor countries. They make up, on average, 2.2% of GDP in North America/Oceania and 2.5% in Europe over the 2026-2100 period, compared with 5.4% in South & South-East Asia and 8.8% in Sub-Saharan Africa.  The gap is particularly large in the early period (when income inequality between regions is enormous). It is shrinking in the second half of the 21^st century (as a consequence of income convergence) [7]See Bothe et al. (2026), Table 3, Figure 6 and Appendix Figure E2b.
 
In our view, country dividends should come with strong conditionalities. Namely, the key objective of the Global Justice Fund is sustainable convergence, and country dividends should be used to finance the new climate investments and human capital expenditure needed to implement this trajectory. Given these objectives, the conditionalities should arguably be based for the most part in terms of measured outcomes, with particular focus on climate targets (investment in low-carbon energy infrastructures, GHG emissions, end of deforestation), human capital targets (education and health expenditure) and inequality targets (distribution of income and wealth). The monitoring of income and wealth inequality is particularly critical, first to properly implement global wealth and income taxes, and next to ensure that country dividends are well used and do not disproportionately benefit the most affluent social groups, either in the public or private sector. Whether the conditionalities should also include explicit sufficiency targets (including reductions in work hours, a shift from material to immaterial sectors, and changes in food habits), or focus only on the resulting GHG emissions, is an open question that should be democratically discussed and decided within the context of the GJF.
 
We present here one possible distribution of country dividends (expressed as a % of world GDP and in constant Euros) between the different expenditure items consistent with the objectives of the Global Justice Platform (Figures 2.4a-2.4b). This split of country dividends into climate investments, health expenditures, and education expenditures is intended to be illustrative of the magnitudes involved. It should ultimately be decided by countries themselves, at least in part. In our view, countries should be given significant degrees of freedom on how to use the country dividends in relation to their other public revenues and expenditures (as long as they achieve the goals set by the GJF). In particular, there are different organisational forms and property structures (including various combinations of public, private, non-profit, and participatory governance) that can be used to deliver the same outcomes in areas such as climate, energy systems, education, and health. There is no reason, from the GJF perspective, to overly restrict country-level experimentation in this area. In our benchmark scenarios, roughly half of these country dividends are to be directed to climate investments and the rest towards health and education expenditure.

One of the central objectives of the Global Justice Platform is to promote equal access to high-quality education and health. As a general goal, all children and all human beings should have access to the widest possible opportunities in terms of education and health – and in principle to equal opportunities, in line with both the capability approach to social justice (Sen, 1979) and the Rawlsian perspective (Rawls, 1971). Most importantly, extended access to education and health should be viewed as the primary driver of social empowerment across all strata of society. To achieve this goal, we project in our benchmark global justice scenario that total education and health expenditure should rise from 13% of world GDP in 2025 (with very large disparities, from 8% in Sub-Saharan Africa and South and Southeast Asia to 23% in North America/Oceania) to about 30% of world GDP in 2050 and 38% in all countries by 2100 [8]See Chancel et al, 2026, Figure 29. One of the core missions of the Global Justice Fund is to help finance this big push in education and health between 2026 and 2050, together with the big push in climate investment.
 
It should be noted, however, that as things stand today, this big push by the GJF is unfortunately going to be insufficient to achieve equal access to education and health in the coming decades. This is because large and extreme inequalities in access to health and education characterize the world. Examining per-capita education expenditures across regions, we find that the figures range from as little as 209 Euros in Sub-Saharan Africa and 425 Euros in South and South-East Asia to as large as 4,100 Euros in North America/Oceania (Figure 2.5a). In other words, per-capita education expenditure is 20 times higher in North America/Oceania than in Sub-Saharan Africa. Given that the school-age population makes up a larger share of the population in poor countries, the gap would be even larger if we were looking at per-child expenditure [9]See Bharti et al (2026) for a detailed analysis taking age structures into account in order to compare education and health expenditure between poor and rich countries. In brief: age effects go in opposite direction for education and health and tend to compensate each other. In our global justice scenario, all countries are projected to converge to 8,400 Euros (PPP 2025) by 2100. However, by 2050, the gap will remain very significant, with per capita education expenditure almost 3 times as large in North America/Oceania and Europe (close to 6,000 Euros) than in Sub-Saharan Africa (around 2,000 Euros) (Figure 2.5b). This would still represent a very large reduction in the gap compared to 2025 (when the gap was 1 to 20), but there would remain substantial inequality of opportunity in access to education for children born in various world regions.

This may seem like a disappointing result, and in some ways it is exactly that: it reflects the fact that, in our view, the Global Justice Platform is a relatively moderate and gradualist platform (arguably too moderate and gradualist). The per capita country dividends distributed to the Global Justice Fund reach about 1,900 Euros at their highest point around 2030-2040, including, in our benchmark simulations, about 420 Euros for education, 630 Euros for health, and 850 Euros for climate investment (Figure 2.4b). These are significant amounts, but they are clearly not sufficient to bridge the education gap expressed in thousands of Euros that we have in 2025 between poor and rich countries (Figure 2.5a). At the same time, the total annual expenditures of the Global Justice Fund already represent about 10% of world GDP on average over the 2026-2060 period, far more than the total resources currently allocated to development aid and international organizations (Figure 2.2).
 
Recent research as part of the Global Justice Project has shown that the annual cost of global equal opportunity in education and health – i.e. the cost of providing to all individuals in the world the same education and health expenditure as the average levels that are currently available in Europe and North America/Oceania – would be around 30-35% of world GDP [10]See Bharti et al (2026), Figures 10a-10c. This does not even include the financial means for climate investment, implying that the Global Justice Fund's total resources would need to be about 40% of GDP (four times larger than in our benchmark scenario) to fully achieve the principles of equal opportunity in education and health. In our view, equal opportunity should remain our moral target, and this is the position which should be advocated if a political deliberation were to take place in a worldwide political community. But this seems completely out of reach in the current state of the world, which is why we revert to a more modest, gradualist approach in our benchmark “global justice” scenario. Although this is not fully satisfactory, the education gap between poor and rich countries is reduced substantially between 2025 and 2050, thanks to the GJF, which would already be a very positive achievement. We will return to the question of scaling up the Global Justice Platform and the appropriate degree of gradualism versus radicalism when we analyze political strategies in Chapter 4.
 
The results we obtain for health expenditure are even more extreme. In 2025, per capita expenditure on health varies from 113 Euros in Sub-Saharan Africa to 8,301 Euros in North America/Oceania (all amounts in PPP 2025 Euros), i.e., a gap of almost 1:80 (Figure 2.6a). Thanks largely to the Global Justice Fund, we project that the gap will be reduced to about 1 to 3 by 2050 (with about 4,000 Euros in per capita health expenditure in Sub-Saharan Africa and 10-12,000 Euros in Europe and North America/Oceania). By 2100, all countries are projected to converge to high-quality health for all, with per capita expenditure equal to 14,400 Euros everywhere (Figure 2.6b). Although this is again more gradual than what the principle of equal opportunity would imply, we believe that this would be a very meaningful achievement.

We again stress that country dividends are not meant to be sufficient to fund all new climate investment and human capital expenditure as envisaged in our benchmark “Sustainable Convergence” scenario. Given the large projected rise in human capital expenditure (from 13% of GDP in 2025, on average at the world level, to 38% by 2100), there is no way this can be financed by the GJF alone. Most of it will consequently have to be financed by national budgets. According to our estimates, the total financial needs associated with our benchmark scenario amount to about 10-12% of world GDP per year over the 2030-2060 period [11]See Chancel et al, 2026, Figure 52, and Bothe et al, 2026, Figure 3. These are lower bound estimates, including a fraction of additional human capital expenditures that are projected over the period, which is significantly larger than country dividends, especially during the 2040-2060 period. The most country dividends can do is to help jumpstart the “Sustainable Convergence” process, especially during the 2030-2040 period, after which country-financed investment will have to play the leading role. The key question is whether this jumpstart strategy can generate sufficient political support – both in the Global South and in the Global North –to be adopted in the first place and sustained in the longer run. 
 
Finally, we have estimated the extent to which the projected rise in human capital expenditure in our benchmark scenario can contribute to global socioeconomic convergence. By using recent estimates of the historical impact of human capital expenditure on productivity (Bharti et al, 2026), we find that the projected rise in human capital expenditure can account for a large fraction (about 50-70%, depending on the regions and the assumptions on parameters) of projected productivity convergence for countries in Sub-Saharan Africa and South and South-East Asia [12]See Bothe et al, 2026, Figure 33. It is worth stressing that the estimated rates of return to human capital expenditure (and particularly to public education and health expenditure) in terms of additional productivity (hourly GDP) appear to be substantially larger in poor countries than in rich countries, which runs against the widespread perception (especially in the North) of less efficient government spending in the South. If anything, governments in the South appear more cost-effective than those in the North at transforming their very limited resources into meaningful socioeconomic outcomes [13]See Bharti et al, 2026, Table 5. The average global rate of return to education and health expenditure appears to be around 10% per year, up to 15-20% or more in poor countries. The main reason explaining why private investors do not finance such high-yield investment – and why public financing is needed – is simply that they cannot appropriate the corresponding human capital assets (for good reasons).

A key pillar of the Global Justice Fund's overall architecture is the World Sovereign Fund, which plays a crucial role in both financing country dividends and reorienting global investment. The creation of the World Sovereign Fund should be viewed as part of a larger attempt to transform the structure of the property regime and to implement a new form of “mixed property” system, including a more balanced distribution between public and private wealth, as well as between private wealth owners and workers.
 
The World Sovereign Fund will be financed by a mix of global wealth and income taxation (the details of which we discuss below). As noted above, the accumulation of the WSF would be made possible by reinvesting a large share of global tax revenue, especially the global wealth tax on the very top wealth holders (billionaires, centimillionaires, decamillionaires), over the 2026-2035 period. According to our benchmark scenario, the assets of the World Sovereign Fund are set to stabilise at about 60% of world GDP around 2035 and remain at this level over the 2035-2100 period. This corresponds to about 10% of the world capital stock. Other (non-WSF) public wealth is scheduled to stabilize around 120% of world GDP (about 20% of world capital stock), so that total public wealth reaches about 30% of national wealth by 2100 (Figures 2.7a-2.7b). Private wealth is assumed to stabilise at about 70% of national wealth, including 65% in personal household wealth and 5% in non-profit wealth (i.e., wealth owned by non-profit institutions) [14]See Bothe et al, 2026, Figure 11. The target which we set for non-profit institutions is similar to the level observed in 2025 in the countries with the largest non-profit sector (including the US).

In effect, according to this scenario, the share of public wealth in national wealth will be back in 2100 to approximately the same level as that observed in 1970 at the world level. Although this is little more than a return to the 1970 world average, it would represent a major political and economic turning point compared with the evolution observed in recent decades. According to our estimates, the share of public wealth in national wealth has declined from 27% in 1970 to 13% in 2025. It has even turned negative (more public debt than public assets) in US-led North America/Oceania and is only slightly positive in Europe, reflecting both the privatization of public assets and the rise of public debt. We see a similar evolution across many regions of the world, but it is worth noting that there are important variations and exceptions [15]See Bothe et al, 2026, Figure 12b. In particular, the share of public wealth in China-led East Asia has stabilized at about 30% of national wealth (with a public share below 10% for housing but over 50% for other capital assets, particularly in the corporate sector) over the past 20 years. Some countries have also developed unusually large sovereign funds, in particular Norway, with net public wealth over 500% of GDP and 60% of national wealth in 2025. More generally, one striking lesson emerging from the comparative and historical study of national wealth is that the structure of property regimes – and especially public vs private wealth patterns – displays large and striking evolutions over time, reflecting major shifts in dominant political discourses, power relations and policy priorities [16]See Bauluz et al (2025). Note that while the World Sovereign Fund, which we envision may seem smaller in relative terms than Norway’s sovereign fund (60% of GDP vs 500% of GDP), the key difference is that the WSF is scheduled to take place at the world level, so that in volume terms it is a lot larger (about 40 times larger than Norway’s sovereign fund) [17]Norway’s GDP represents 0.3% of world GDP, and its sovereign fund about 1.5% of world GDP.
 
The shift to this new form of “mixed property” system, which we project over the 2026-2100 period, serves two main purposes within the context of the Global Justice Platform. First, the World Sovereign Fund provides significant investment income, playing a crucial role in financing country dividends on a long-term basis. Next, the rise of the public share in national wealth – both via the World Sovereign Fund and via non-WSF public wealth – will contribute to reorienting investment flows toward sustainable development. As noted above, both effects are large and comparable in magnitude. For instance, during the 2026-2100 period, we project that the Global Justice Fund distributes on average 4.3% of world GDP per year in country dividends and controls 3.5% of world GDP in investment flows (Table 2.1). Historical and contemporary evidence suggests that an excessive reliance on private ownership makes it more difficult to pursue sustainability objectives and to resist profit-making pressures (including in the energy sector), and conversely that public control over a substantial fraction of investment flows can contribute towards setting new environmental and social rules (both in the energy sector and other sectors) [18]See Chancel (2025) and Chancel and Mohren (2025).
 
Several remarks should be made about this scenario. Generally speaking, we certainly do not mean that all countries should adopt the same property regime. What matters most from the viewpoint of the Global Justice Platform is the size of the World Sovereign Fund (to finance adequate country dividends and reorient investment flows) and the fact that all countries follow the Sustainable Convergence trajectory (especially regarding human capital expenditure and the low-carbon energy transition).  In our benchmark scenario, all countries are assumed to have a domestic capital stock converging to approximately 600% of GDP by 2100, including about 280% in housing (dwellings and land underlying dwellings) and 320% in other capital assets (other buildings, equipment, machinery, energy and transport infrastructures, etc.) [19]See Chancel et al (2026), Figure 10 and Appendix Figure Jk2. The exact details of the property regime – i.e., who owns these different capital assets and under what rules – should be left to country-level experimentation. The perfect combination of public, personal and non-profit wealth remains to be invented, and all countries should participate in this process of collective learning and experimentation, for instance, regarding the role of workers' representatives, citizens' involvement, and voting procedures in the various forms of organization. Some countries might decide to allocate more than 20% of non-WSF public wealth in national wealth (such as China or Norway today, with very different underlying governance rules). Others might opt for a lower share, for instance, because they rely more extensively on non-profit institutions and/or workers’ representatives in privately owned corporate organizations.
 
More generally, the target property regime which we set for 2100, namely 30% for public wealth (including 10% for the World Sovereign Fund and 20% for other public wealth) and 70% for private wealth (including 65% for personal wealth and 5% for non-profit institutions), should be viewed as merely indicative. In practice, the exact governance rules within each sector can matter even more than the sectoral shares. For instance, the co-management or codetermination rules which have been applied in Germany and Nordic Europe since the 1950s (with up to 50% of voting rights for workers representatives in corporate boards in large companies, independently from any equity ownership) could be extended to all countries and organizations (irrespective of size), together with a limitation of voting rights to 10% for individual shareholders in large corporations (say, with more than 100 employees, with a gradual cap for smaller firms). In the event such a system were in place, it is unclear whether this should still be described as “private property” or whether it would be more appropriate to call it “mixed property”, “socialized property”, or “worker-managed property” [20]This system has been described as a form of “participatory socialism” by Piketty (2020; 2022, Figure 18). See also Ferreras (2026) for a synthesis of proposals on economic democracy and McGaughey (2025) for an analysis of the changing frontier between public and private ownership. Our own preference would be to move as far as possible towards worker-managed organizations and participatory governance, within a broader process of decommodifying the economy [21]See the discussion in Chapter 1. See also Piketty (2025). Accelerated decommodification would likely imply an accelerated compression of the capital share and a corresponding change in the GJF financing structure (less investment income, but more non-financial benefits associated to sustainable investment and/or more global income tax revenue thanks to higher labour incomes). See the discussion below. But this is clearly an area where a lot can be learned from the diversity of country experimentation strategies. There is no reason to restrict in advance the directions this collective learning process should take.
 
We now come to the WSF investment strategy. Generally speaking, there are many issues regarding the functioning of the WSF for which we do not aim to provide complete answers. These issues should be discussed extensively and democratically in the context of the Global Justice Fund. Given the magnitude of the country dividends and the importance of the conditionalities attached to these dividends (see Chapter 2.2), it is probably justified to start with a relatively centralized system, in the sense that the WSF should be administered at the level of the GJF as a whole, at least over the 2026-2050 period. It is also possible to envision a more decentralized system, especially during the 2050-2100 period, as global socioeconomic convergence becomes more pronounced. By the end of the 21^st century, when the convergence process is over, it might make sense to hand over to the national governments the full control of the country shares in the WSF. One may also argue that it is useful to keep significant resources (about 10% of the world capital stock) under shared democratic control at the global level on a permanent basis.
 
In our benchmark simulations, we assume that the WSF invests its resources in a balanced portfolio of capital assets that is representative of the world capital stock as a whole. The gross return on these capital assets is therefore assumed to follow the same evolution as the world gross rate of return to capital, which is assumed to gradually decline over time, in line with the projected rebalancing of capital and labour shares (an evolution which could go even further) [22]See Bothe et al, 2026, Figures 14a-14d. The gross capital share rose from 38% of world GDP in 1970 to 46% in 2025 and is projected to decline to 36% by 2100. The net capital share (after deduction of consumption of fixed capital) rose from 28% of world NDP in 1970 to 34% in 2025 and is projected to decline to 24% by 2100. Given the projected rise in capital-output ratios, this implies that the gross rate of return drops from 8.9% in 2025 to 6.0% in 2100 (and the net rate of return from 5.4% to 3.4%). Note that the rise of the capital share over the 1970-2025 period is due to a multitude of economic, political and institutional factors, in particular the rising bargaining power of capital owners, the decline of unions and the deregulation of global capital flows. Reverting this trend requires substantial policy changes, including new labour market institutions and increased voice and power for workers representatives. Going further in the direction of reduced capital shares would compress the flows of WSF investment income but entails benefits in other dimensions, namely by raising labour income flows going to large segments of the population. GJF financing strategy would need to be adapted to the new situation, e.g. by raising more revenue on upper and upper-middle labour income earners via the global income tax. In addition, we assume that the WSF issues public debt equivalent to about 30% of world GDP in the long run, so that the total assets invested by WSF can stabilize at about 90% of world GDP, with net WSF wealth equal to 60% of world GDP. For the sake of completeness, we also assume that non-WSF public debt will stabilize at 60% of world GDP in the long-run, with non-WSF public assets equivalent to 180% of world GDP and net non-WSF public wealth equal to 120% of world GDP [23]See Bothe et al, 2026, Figure 13.
 
Several remarks should be made about these assumptions. First, the assumption that WSF assets earn the average world return on capital can be viewed as relatively conservative. If the only objective of the WSF were to generate the largest possible investment income, then it would certainly be possible to do better [24]In particular, the average gross return to capital is substantially larger in the South than in the North, so that the WSF could increase significantly its investment income by investing a bigger share of its portfolio in Sub-Saharan Africa or in South & Southeast Asia than their share in world GDP and capital stock (which would also make sense from the viewpoint of sustainable convergence). In addition, the world capital stock includes a sizable stock of relatively low-return assets like housing and especially government buildings and infrastructures (whose net return is conventionally set to zero in national accounts, which a sovereign fund might choose to ignore in order to maximize its financial returns). On the other hand, there are good reasons why the WSF might also use non-financial criteria in its portfolio choices. In our view, the WSF should contribute to reorienting global investment toward sustainable development, which implies that its portfolio choices should be based on ambitious environmental and social criteria, even if this comes at the cost of lower returns (but with other non-financial benefits) [25]In case the investment choices of the WSF lead to lower total investment income than our benchmark projections, then country dividends might need to be reduced accordingly. But in principle this should be compensated by the fact that these lower financial returns come with non-financial benefits in terms of sustainable development, which reduces the needs for country dividends. The right balance should be set by GJF and WSF governance bodies after extensive deliberation. Similarly, we cannot decide in advance to what extent WSF assets should concentrate on certain sectors, such as low-carbon energy infrastructure (which would make sense given WSF’s missions), or play a significant role in all sectors (to influence environmental and social norms across the economy, which also makes sense). 
 
Next, regarding public debt, our benchmark assumptions can also be viewed as relatively conservative. Total public debt is about 109% of world GDP in 2025 and is projected to decline to 90% of world GDP by 2100 (including 30% in WSF debt and 60% in non-WSF public debt). The main reason for this assumption is that one of the objectives of the Global Justice Platform is to reduce the overall financialization of the economy (i.e., the overall size of financial assets and liabilities relative to real economic variables such as GDP or the capital stock) [26]In particular, we aim to reduce the size of cross-border financial assets and liabilities. Total gross financial assets and liabilities have increased from 20% of world GDP in 1970 to 64% in 1990 and 218% in 2025, and in our benchmark projections we aim to reduce them back to 64% by 2100. See Bothe et al, 2026, Appendix Figures B4a-B4d. On the other hand, allowing for larger public debt would enable the WSF (and national governments) to benefit from a stronger leverage effect and to own a larger share of the economy’s productive assets [27]See Bothe et al, 2026, for a more detailed discussion. The most natural solution would be to denominate WSF public debt in international currency, by using the UNC (United Nations Currency), which, according to the Global Justice Report, should be issued by the UNCB (United Nations Central Bank), as described in further detail in Chapter 3. In case this is not possible, WSF public debt could also be denominated on the basis of a basket of currencies, for instance, by applying the same weights currently used by the IMF for issuing SDRs (Special Drawing Rights) [28]In any case, we assume in our benchmark scenario that all countries will pay the same low nominal interest rate on their public debt over the 2030-2100 period (3%), thanks to the reform of the monetary system and the creation of an International Clearing Union (ICU). See Chapter 3 and Bothe et al (2026).
      
According to our benchmark estimates, the World Sovereign Fund is set to generate total investment income of around 4.8% of world GDP on average over the 2026-2100 period (see Table 2.1), including 4.0% without the leverage effect from WSF public debt issuance and 0.8% from the leverage effect [29]See Bothe et al, 2026, Table 8. Given that the public debt issued by the WSF is likely to be a particularly safe and liquid asset, it is possible that it will benefit from an even lower interest rate, which would amplify the leverage effect. The same would happen if the WSF issues more debt than in our benchmark scenario. Conversely, in case the WSF issues no debt at all, then the investment income would be reduced by about 0.8% of world GDP on average over the 2026-2100 period, and the country dividends would need to be reduced accordingly.

We now move to the revenue side of the Global Justice Fund, namely the global wealth and income taxes. As discussed in Chap. 2.1, the global wealth tax on top wealth holders is crucial for kickstarting the sustainable growth path envisaged by the Global Justice Platform. The basic structure of the global wealth tax schedule, which we propose to apply in our benchmark scenario, is described in Table 2.2. Tax rates rise gradually from 0% at the level of 10 times average world per adult wealth (about 1.1 million Euros in 2026) to 1% at 20 times average wealth (2.2 million), 3% at 50 times average wealth (5.5 million), 5% at 100 times average wealth (11 million), 10% at 500 times average wealth (55 million), 15% at 1000 times average wealth (110 million) and 20% at 5000 times average wealth (550 million). Tax rates are expressed as effective tax rates and are assumed to rise linearly between thresholds. For instance, with wealth equal to 15 times the average wealth, the effective tax rate is 0.5%. Similarly, with wealth equal to 3000 times the average wealth, the effective tax rate is 17.5%. Above 5000 times the average wealth, the effective tax rate is stable at 20%. All billionaires pay a global wealth tax equal to 20% of their wealth [30]Thresholds and effective tax rates have been set so that implicit marginal tax rates follow smooth patterns and are always below 100%. See Bothe et al, 2026, Appendix Table TE4f for full tax schedule.

Although the exact details regarding the thresholds and tax rates are merely illustrative, the orders of magnitude are important. The tax schedule was set to generate the tax revenues needed for the Global Justice Platform and the Sustainable Convergence scenario. The exact tax rates and thresholds can vary somewhat, but if they change by too much, then it might not be possible to finance the same policies (low-carbon energy infrastructures, education and health expenditures, etc.) and achieve the same climate objectives (with temperature rise limited to 1.8°C by 2100 in our reference scenario rather than 4.5°C or more under current policies).
 
From a historical perspective, the closest precedent to the kind of wealth tax that we are proposing here are the exceptional progressive wealth taxes that were successfully applied in the aftermath of World War 1 and World War 2, with top tax rates around 50-90% or more in many countries (including Germany and Japan). At the time, these policies were designed to fulfil multiple objectives, including funding post-war reconstruction, compensating low- and middle-wealth households who had been most affected by the war, and curbing the power and influence of the very top wealth holders [31]In Germany, the “Lastenausgleich” (“burden-sharing”) system set up after World War 2 included a top wealth tax rate equal to 50% for the largest wealth holders. In Japan, the top wealth tax rate was 90%. In France, the “Impôt de solidarité nationale“ (ISN) set up in 1945 included a top tax rate equal to 20% on top wealth holders and 100% on the wealth increment for taxpayers with rising nominal wealth between 1938 and 1945. Exceptional wealth taxes were also applied in many other European countries after World War 1 and again after World War 2. On the history of these exceptional wealth taxes and other capital levies, see e.g. Eichengreen (1990), Hughes (1999) and Piketty (2020, 2022). The current situation shares some important similarities with the postwar context, in particular, the need to raise significant resources to meet today’s development and environmental challenges. That being said, there are also many important differences. In particular, we are considering the possibility of a global wealth tax rather than a national tax (in line with today’s global warming challenges) and of a permanent tax (rather than a one-off exceptional tax) [32]The main advantage of permanent wealth taxes over one-off taxes is that they can prevent wealth concentration to rise again to extreme levels in the future. In practice, the frontier between permanent and one-off wealth taxes is relatively fluid. For instance, the exceptional wealth taxes set up after World War 2 could often be paid over several years (sometimes several decades). Conversely, the permanent wealth tax advocated here raises most of its lifelong revenues in its early years.
 
We should also make it clear that the global wealth tax applies to all forms of wealth, including housing, business assets, and financial assets (net of financial liabilities), without any exemptions. For very top wealth holders (e.g., billionaires subject to the 20% effective tax rate), the global wealth tax will generally be much larger than their annual income, so the only way to pay the tax will be to sell assets. This can generally be done in two ways. The simplest way is to pay the tax in securities [33]This method was frequently used in the past, in particular in the context of postwar exceptional wealth taxes. See e.g. Brassac (2026) about the French ISN. The tax could be paid in shares and other securities, which were then allocated to the “Société nationale d’investissement” (a sovereign fund). In effect, taxpayers can transfer the corresponding assets to the World Sovereign Fund, which can later decide to retain them or reshuffle its portfolio. The other way is to sell assets to other individuals, typically to less wealthy individuals who are not subject to high tax rates (or might even benefit from GJF transfers and new policies), and to use the proceeds to pay the tax. The GJF and/or national governments may also decide to encourage asset purchases by other individuals, for instance, by employees of the companies in question, to promote participatory governance and workers’ empowerment [34]This could come together with legislative changes granting more voting rights for employee representatives in corporate boards (independently from equity ownership).
 
According to our simulations, about 1.3-1.5% of the world population is subject to the global wealth tax over the 2026-2050 period (mostly coming from the richest regions), and less than 0.5% of the world population after 2060 (with a more balanced regional distribution) (see Figure 2.8a). The decline in the fraction of taxpayers follows from the endogenous fall in wealth concentration, which is itself due to the wealth tax (as top wealth holders must transfer or sell assets to pay it) and to the decline in income concentration (as we shall see below). For simplicity, we assume that the same wealth tax schedule (with bracket thresholds expressed as multiples of average world wealth; see Table 2.2) applies throughout the 2026-2100 period [35]With only minor changes for bottom brackets. See Bothe et al (2026) for a detailed analysis.

Note that the fraction of wealth tax taxpayers varies significantly across regions over the 2026-2050 period: up to 4-7% of the population in the richest regions (Europe, North America/Oceania), and less than 0.5% in the poorest regions (Sub-Saharan Africa, South & South-East Asia). The fraction of taxpayers then falls below 0.5% of the population in all regions after 2060 (see Figure 2.8b). It is worth stressing that all millionaires and billionaires of the world are treated in the same manner by the global wealth tax: what matters is the level of their wealth, not where they come from.

To better understand the structure of wealth tax revenues, it is useful to look in more detail at the bracket-level simulation results. In 2026, we have about 1.3% of the world population paying the global wealth tax, including 0.9% (about 52 million adults) in the bracket going from 1.1 to 2.2 million Euros in per adult wealth, 0.3% (19 million adults) in the 2.2-5.5 million bracket, 0.1% (5 million adults) in the 5.5-55 million bracket, 0.004% (217 thousands adults) in the 55-552 million bracket and less than 0.001% (29 thousands adults) in the last bracket (552 million and over) (Table 2.3). Given that there are often two adults per household, the last bracket can be viewed as the “billionaire class”, i.e. couples with more than 1.1 billion Euros in net wealth. For the sake of concreteness, we will also refer to the 55-552 million bracket as the “centimillionaire class” (couples with wealth in 110m-1.1b range), the 5.5-55 million bracket as the “decamillionaire class” (couples in 11m-110m range) and the 1.1-5.5 million bracket as the “millionaire class” (couples in 2.2m-11m range) [36]The tax brackets are defined as multiples of average world wealth, so the exact levels vary over years. All WID series on wealth and income distribution are available both in per adult and per capita terms. Our raw sources are usually expressed in per adult terms (e.g. tax data is often available at the individual level, or at the married couple level in some countries, in which case we divide income and wealth by two in the absence of any other information). At the world level, total population is about 1.48 times adult population in 2026 (8.291 billion vs 5.604 billion), so that per capita average income and wealth levels are on average about 1.48 time smaller than per adult average levels. Our estimates are broadly consistent with Forbes billionaire lists. See Bothe et al, 2026, section 2.2 for a detailed comparison.

If we look at tax revenues by wealth bracket, the striking result is that millionaires, decamillionaires, and centimillionaires pay more in taxes than billionaires, despite the fact that we use steeply progressive tax rates. In 2026, billionaires do pay very substantial revenues: 4.2% of world GDP, according to our simulations. Taken together, other taxpayers pay even more: 6.1% of world GDP, including 1.0% for millionaires, 2.4% for decamillionaires and 2.7% for centimillionaires (see Figure 2.9a). This result is even more striking when we cumulate tax revenues over several years. Namely, over the 2026-2035 period, cumulated wealth tax revenues represent 64.2% of world GDP, including 16.2% paid by millionaires, 19.7% by decamillionaires, 16.5% by centimillionaires and 10.8% by billionaires (see Figure 2.9b). Generally speaking, tax revenues from the highest wealth brackets tend to decline quickly over time, as the corresponding taxpayers cede their assets to pay the tax. This illustrates why, in order to generate sufficient revenue, the global wealth tax proposed in the Global Justice Platform cannot rely solely on billionaires. 

The basic structure of the global income tax schedule, which we propose to apply in our benchmark scenario, is described in Table 2.4. Tax rates rise gradually from 0% at the level of 7 times average world per adult disposable annual income (149 100 Euros in 2026) to 5% at 10 times average income (213 000), 20% at 20 times average income (426 000), 40% at 50 times average income (1.1 million), 50% at 100 times average income (2.2 million), 70% at 500 times average income (11 million), 80% at 1000 times average income (22 million) and 90% at 5000 times average income (110 million). As with the wealth tax, tax rates are expressed as effective tax rates and assumed to rise linearly between thresholds. For instance, with income equal to 8.5 times the average income, the effective tax rate is 2.5%. Similarly, with income equal to 3000 times the average income, the effective tax rate is 85%. Above 5000 times the average income, the effective tax rate is stable at 90% [37]Thresholds and effective tax rates have been set so that implicit marginal tax rates follow smooth patterns and are always below 100%. See Bothe et al., 2026, Appendix Table E5f for full tax schedule.

Several points are worth stressing about this tax schedule. First, like the global wealth tax, the global income tax operates alongside national tax systems and targets the very top of the global income distribution. This also explains why the global income schedule is expressed as a function of post-tax net disposable income, i.e. after deducting all country-level income taxes and other taxes. This provides an incentive for countries to compress their income distributions further. In case they do not reduce sufficiently the level of their top incomes (via taxation or other policies such as rigid salary scales or other schemes; more on this later), then they will pay higher global income tax liabilities to the Global Justice Fund.
 
Next, although the global income tax plays a smaller role than the global wealth tax in the Global Justice Platform, we stress that income tax revenues are significant: 4.0% of world GDP on average in 2026-2035, vs 6.7% for wealth tax revenues (see Table 2.1 and Figure 2.3a). According to our simulations, about 1.0-1.1% of the world population is subject to the global income tax over the 2026-2050 period (mostly coming from the richest regions), and less than 0.5% of the world population after 2060 (with a more balanced regional distribution) (Figure 2.10). The decline in the fraction of taxpayers follows from the fall in country-level income concentration (as we shall see below). For simplicity, we assume that the same global income tax schedule (with bracket thresholds expressed as multiples of average world income, see Table 2.4) applies throughout the 2026-2100 period [38]With only minor changes for bottom brackets. See Bothe et al (2026) for a detailed analysis. Note that the fraction of taxpayers varies significantly across regions over the 2026-2050 period: up to 4-7% of the population in the richest regions (Europe, North America/Oceania), and less than 0.5% in the poorest regions (Sub-Saharan Africa, South & South-East Asia). The fraction of taxpayers falls below 0.5% of the population in all regions after 2060 [39]See Bothe et al. (2026), Figure 9b.

We stress again that all high-income earners worldwide are treated the same way: what matters is their income level, not where they come from. Note also that we define income thresholds and tax rates using PPP Euros (based upon purchasing power parities) in our benchmark simulations, which means that high-income taxpayers in poor countries will pay high taxes even if their MER income (using market exchange rates) is not so high. In our view, this is the most meaningful way to proceed, as PPP income levels arguably provide the most comparable estimates of living standards across countries [40]For consistency reasons, we do the same for the wealth tax. In case we were using MERs rather than PPPs to define the thresholds and tax rates used in the global income and wealth tax schedules, then we would have more taxpayers and higher taxes in rich countries and fewer taxpayers and lower taxes poor countries which we now have. Global tax revenues would be little affected.
 
There are many historical precedents – at the national level – of the steeply progressive income tax that we are proposing here at the global level. Most developed countries applied very high tax rates (70-80% or more) to their highest income earners at one point or another during the 1920-1990 period. In particular, the top tax rate used in the US federal income tax was equal to 81% on average over the 1930-1980 period (without even including state and city-level income taxes). Available historical evidence shows that this contributed to a sharp compression of the income scale, and that this did not entail any measurable negative impact (and possibly had a positive effect) on productivity growth. High top tax rates appear to curb the market power and pay-setting capacity of top managers and other top earners. This benefits lower-income earners in their companies (who can bargain for better wages) and the economy in general, without creating a noticeable distortion (but rather by removing one) [41]See Andreescu, Arias-Osorio et al (2025). See also Piketty (2020, 2022). In effect, once the market power and pay-setting capacity of top managers and other top earners is taken into account, optimal tax rates on very high incomes can easily reach 80-90%. For theoretical models and empirical calibrations, see Piketty and Saez (2013) and Piketty, Saez and Stantcheva (2014).
 
As with the wealth tax, it is useful to analyze the bracket-level simulation results in more detail. In 2026, we project that we have about 1.1% of the world population paying the global income tax, including 0.5% (about 30 million adults) in the bracket going from 149k to 213k Euros in per adult disposable income, 0.4% (23 million adults) in the 213k-426k bracket, 0.1% (7 million adults) in the 426k-1.1m bracket, 0.025% (1.4 million adults) in the 1.1-2.1 million bracket, 0.01% (551 thousands adults) in the 2.1-21 million bracket, and less than 0.001% (29 thousands adults) with 21 million and over (Table 2.5). As one can see from the simulations, all tax brackets are important to generate large income tax revenues (4.5% of world GDP in 2026). If one were to rely solely on individuals with several million euros (or several dozen million euros), then tax revenues would be divided by two or more; it is also critical to tax individuals with several hundred thousand euros [42]See Bothe et al. (2026), Figures 10a-10b. Generally speaking, tax revenues from the highest income brackets will tend to decline quickly over time in our benchmark scenario. This is due to the cumulated impact of the global income tax itself (which reduces the market power and pay-setting capacity of top managers and other top earners), the global wealth tax (which reduces wealth concentration and therefore top capital income flows) and most importantly, the country-level policies implemented to compress the income distribution (more on this below).

One of the central objectives of the Global Justice Platform is to achieve a substantial compression of the income and wealth scales over the 2026-2100 period. As noted above, global wealth and income taxes are designed both to raise the resources needed to finance the GJF and to curb the concentration of income and wealth at the top of the global distribution. At the same time, country-level policies – including country-level progressive income and wealth taxation, minimum wage policies, pay scale regulations, labour market rules, co-determination and workers’ representation on corporate boards – are expected to play the leading role in reshaping the domestic distribution of income over the long run.
 
According to the Global Justice Platform, the income scale within each country is projected to converge to a range of 1 to 5 over the 2026-2100 period. More precisely, the ratio between percentile thresholds P99.9 and P10 of the distribution of post-tax, posttransfer distribution of per capita net national disposable income (including all in-kind transfers), as defined by DINA Guidelines [43]See Chancel et al (2025), is projected to converge to 4.5 in all countries, with an absolute maximum gap of 1 to 5 (Figure 2.11a) [44]By definition, the percentile threshold P99.9 corresponds to the income level above which 0.1% of the population is located, and the percentile threshold P10 to the income level below which 10% of the population is located. The absolute maximum gap of 5 corresponds to the ratio P99.999P100/P0P1 between the average income of the top 0.001% (P99.999P100) and the bottom 1% (P0P1), i.e. the top and bottom g-percentiles used in WID series. See Bothe et al. (2026), Appendix A.

Taking as given the trajectories of country-level post-tax income distributions, we simulate the endogenous evolution of country-level wealth distributions over the 2026-2100 period, based on simulated global wealth and income payments and the projected evolution of the saving-rate profile by percentile [45]Simulations are computed at the level of the 57 WID core territories (i.e. 48 main countries + 9 residual regions) and of the 127 WID generalized percentiles (from the bottom 1% to the top 0.001%), making a total of 7239 country-gpercentile cells used to describe the world wealth distribution at any point in time. See Bothe et al (2026) and the online replication package and computer codes for full details. Given our assumptions about the long-run profile of saving rates, the steady-state wealth distribution corresponds to a wealth scale of about 1 to 10 within each country (Figure 2.11b) [46]In practice, our simulated wealth distributions in 2100 are very close to the target steady-state distribution. I.e. the bottom 50% wealth share rises to 30% of total wealth (vs 31% for the target) and the top 10% wealth share drops to 24% (vs 22% for the target).

 
There are two main justifications for this objective of reducing income and wealth inequality. First, historical evidence shows that this evolution stands in the continuation of a highly successful long-run movement toward equality and prosperity, especially in Nordic and Western Europe (Andreescu, Arias-Osorio et al, 2025; more on this below). Next, because average monetary incomes will rise less quickly in our benchmark scenario over the 2026-2100 period than in the absence of sufficiency, it is critical to compress the income scale so that low- and middle-income groups are more strongly inclined to support such a strategy, especially in today’s rich countries.
 
In our benchmark scenario, the ratio between the post-tax income threshold of the 99^th percentile and that of the 10^th percentile (P99/P10) is projected to decline from about 37 today (ratio of population-weighted country thresholds) to 3.3 by 2100. Such a compression is very much in line with historical developments observed in Western and Nordic Europe during the 20^th century. In effect, the P99/P10 ratio declined from about 32 in 1900 to 3.9 in 1990 in Nordic Europe (Figure 2.12a). In other words, what we are projecting for the world as a whole over the 2026-2100 period is of the same order of magnitude as what has already been achieved – over a similar time horizon – in the most advanced European countries during the 20^th century.

The picture is very similar, albeit starker, if we focus on the P99.9/P10 ratio, which captures the gap between the thresholds of the 99.9^th percentile (the top 0.1%) and the 10^th percentile. This ratio is projected to decline globally from about 130 today to about 4.5 by 2100, against a historical decline from about 150 to 11 in Nordic Europe during the 20^th century (Figure 2.12b).

Figure 2.13a summarises the historical compression of the post-tax income distribution in Nordic Europe over the 20^th century and the projected evolution for the future. The share of the top 10% of incomes in total income is projected to continue its historical decline, from 52% in 1910 to 24% in 2025 and 18% by 2100. Similarly, the bottom 50% income share is projected to rise from 17% in 1910 to 33% in 2025 and 38% in 2100. In effect, the projected inequality compression for the 21^st century is relatively modest as compared to the compression that already took place over the 1910-1990 period.

Figure 2.13b plots the same evolution for the wealth distribution. In Nordic Europe, the share of the top 10% wealthiest holders in total personal wealth fell from over 80% in 1910 to about 50-55% since 1980-1990. We project that the top 10% share will fall below 25% by 2100, mostly benefiting the bottom 50%, which until now has had a very small share of total wealth. This evolution follows from the cumulative impact of the projected compression of income inequality and the flattening of saving rate profiles (an evolution that the introduction of universal inheritance could facilitate) [47]The main rationale for the projected flattening of the saving profile is the compression of the income scale itself: low-income percentiles now have more resources to save and do not need to consume everything in order to reach adequate living standards, and conversely high-income percentiles have less resources to accumulate if they want to keep certain standards. The saving profile can also be influenced by changing social norms about consumption and by policies aimed at raising saving incentives and/or at promoting specific saving vehicles (e.g. zero-interest loans in order to encourage home ownership or business creation), or even more directly by the redistribution of inheritance. See e.g. Piketty (2022) for a minimal inheritance scheme equal to 60% of average wealth (and allocated to each young adult at age 25) financed by progressive inheritance and wealth taxation. While we do not model explicitly the impact of such policies, this is likely to be one of the most effective ways to flatten the saving profile to the level assumed here. See Bothe et al, 2026, Figure 24.

 
By combining the projected compression in between-country and within-country inequality, we obtain our simulation results for the global distribution of income and wealth (Figures 2.14a-2.14b).

We find the redistribution of wealth to be particularly striking. The share of the bottom 50% of the world wealth distribution is projected to rise from about 2% of total personal wealth in 2025 to about 30% by 2100 (Figure 2.15a). Symmetrically, the wealth share of the top 0.001% - corresponding in 2025 to about 80 thousand individuals with an average per capita wealth of around 500 million Euros, i.e. broadly the world billionaire class - is projected to decline from 6.4% in 2025 to 0.05% by 2100 (Figure 2.15b) [48]Note that this top 0.001% “billionaire class” (about 80 thousand individuals out of 8 billion) is somewhat larger than the billionaire group defined by the top wealth tax bracket, which includes approximately 30 thousand adults (i.e. a total population of about 45 thousand individuals). See Table 2.3. In other words, the share of personal wealth held by the bottom half of the world population is multiplied by about 15, while the wealth share of the world billionaire class is divided by more than a hundred. By 2100, the regional composition of all wealth groups reflects approximately the regional distribution of the world population, as average wealth levels and wealth distributions converge across countries [49]See Bothe et al, 2026, Figures 21a-21g, 26a-26g, 34a-34h and 37a-37g for a detailed analysis of the past and projected evolutions of regional bottom and top shares and levels, both for income and wealth. The average annual per capita income of the bottom 50% rises from little more than 2k Euros in 2025 to 38k in 2100, while the average income of the top 0.001% drops from about 25 million Euros to 164k. The average per capita wealth of the bottom 50% rises from about 2k to 140k, while the average wealth of the top 0.001% drops from about 500 million to 2.2 million. The wealth scale has not completely converged to its steady-state level of 1-to-10 by 2100, but it is getting close.

Perhaps the most important point to stress in this context is that the 20^th-century compression of the income scale did not come at the expense of prosperity. On the contrary, the countries that experienced the most substantial reduction in top-end inequality over this period – typically Nordic and Western Europe – are also those that experienced some of the most impressive productivity gains (Figures 2.16a-2.16b). Hourly labour productivity – measured as GDP per hour worked, in PPP 2025 Euros – rose to unprecedented levels in Western and Nordic Europe during precisely the decades (1910-1990) when the income scale was most drastically compressed. More generally, the long-run historical record of the richest industrial economies clearly shows that very sharp declines in top-end inequality have been fully compatible with – and possibly have contributed to – very high rates of productivity growth and rising living standards. The experience of countries like the United States, which underwent a partial reversal of inequality during the 1980-2025 period, provides further evidence on this point. The United States, where top income inequality has risen markedly since the 1980s-1990s, does not exhibit higher productivity growth than Western Europe over the same period. Given their greater human capital investment, the US should have significantly higher productivity than Nordic Europe, and the fact that it has somewhat lower productivity suggests that the higher equality observed in Nordic Europe might have a positive residual effect [50].e. the potentially positive inclusiveness effect associated to higher equality seems to be larger than the potentially negative incentive effect. This could also reflect the higher cost-effectiveness of public education and health expenditure over private expenditure. It is well-known that higher private health expenditures in the US come with significantly worst health indicators relative to Europe. Existing estimates also suggest that a higher cost-effectiveness of public education expenditure over private education expenditure (in terms of their impact on productivity growth). See Bharti et al (2026).

On the other hand, the experience of countries like China and India, where high growth since the 1980s and 1990s was accompanied by rising top-income concentration, may suggest that inequality is necessary for growth. In the case of China, productivity growth has risen substantially since 1980, but one can plausibly argue that this has little to do with rising inequality and rather with the end of central planning and the development of a more decentralized economic system. A similar argument can be made for India: the upsurge of growth since 1990 has arguably more to do with the abandonment of some of the ill-conceived policies of the previous period than with rising inequality per se. It is also striking that India has much more inequality than China but much lower productivity growth, which can, however, also be explained by larger and better-targeted human capital expenditure in China [51]See Bharti and Yang (2024). It is also interesting to note that we observe substantially lower levels of inequality in Western Europe and especially Nordic Europe over the 1980-2025 period than in China during the Maoist period (1950-1980) or in Russia during the Soviet period (1920-1980). See Andreescu, Arias-Osorio et al, 2025, Figures 28-31. In other words, the problem with Maoist China or Soviet Russia does not seem to be an excessive level of equality in itself, but rather a specific set of policies and institutions (i.e. communist central planning rather than social-democratic welfare state).
 
Taken together, these comparative and historical observations suggest that the equality targets envisaged by the Global Justice Platform are within the realm of historical experience and that there is no strong evidence to assume that such a reduction in inequality would necessarily be detrimental to prosperity. Controlling for levels of education and health expenditure, econometric evidence might even suggest that higher equality could entail a positive residual effect on productivity [52]See Andreescu, Arias-Osorio et al, 2025, Tables 3-4. This positive effect is consistent with recent studies using experimental transfer programs (Banerjee et al, 2021; Balboni et al, 2022). Unfortunately, such experimental studies can look only at redistributive changes of limited macro magnitude. This positive effect is also consistent with larger scale studies using historical experiments from major land reforms, which typically find that land redistribution and stronger land tenure rights for poor peasants tend to raise productivity due to inclusiveness and empowerment effects See e.g. Banerjee et al (2002) and Banerjee and Iyer (2005). On the other hand, it is certainly possible to find examples of ill-functioning land reforms with poor efficiency impacts. Because these estimates are highly uncertain, however, we choose to assume in our benchmark simulations that inequality has zero impact on productivity – neither positive nor negative. At the end of the day, only through new historical experimentation and institutional development will we be able to determine how far the historical march toward equality can go in the future [53]There are so many time-varying differences between countries and historical contexts (e.g. regarding Western and Nordic Europe vs. the US, or China vs. India, or successful vs unsuccessful land reforms) that it is illusory to imagine that econometric evidence alone can settle such a complex issue. Statistical language should of course be brought to the democratic discussion, but with no pretention to close it.
 
We should finally stress that the compression of the income scale, which we project here, is to be achieved primarily through country-level policies, with the global income tax playing the role of a backstop incentive device (see Chap. 2.5). There are many different ways in which countries can proceed to compress their income distribution. These include progressive income and wealth taxation, minimum wage policies, pay scale regulations in the public and private sectors, co-determination and workers’ representation on corporate boards, limitations on the voting rights of individual shareholders in large corporations, support for collective bargaining and trade unions, and many other tools. In theory, one could reduce post-tax inequality entirely through taxes and transfers; that is, one could keep the same level of pre-tax inequality throughout the 2026-2100 period in all countries and adjust the country-level tax schedules and transfer systems to deliver the desired level of post-tax, post-transfer inequality. Available historical evidence, however, suggests that it might not be the most appropriate way to proceed. Namely, in practice, the substantial compressions of post-tax inequality which took place over the course of the 20^th century – particularly in Nordic and Western Europe – relied to a large extent on the compression of pretax inequality (“pre-distribution” or “pre-tax redistribution”, as opposed to “post-tax redistribution”), thanks to multiple transformations of progressive tax systems (which have a strong impact on pre-distribution and not only on ex post redistribution), labour market institutions (including minimum wages, salary scales, collective bargaining, etc.), democratic governance rules, inclusive educational reforms, and so on [54]See Blanchet, Chancel and Gethin (2022) and Bozio et al (2024) for detailed analysis. The Global Justice Platform does not prescribe a single model and leaves country-level experimentation as the primary mode of social learning in this area. There are strong arguments in favour of pre-distribution, but countries should, in our view, have the choice over the exact set of policy tools and institutional reforms they want to implement, as long as they converge on a sufficiently compressed distribution, so as to meet the objectives of sustainable convergence and global justice [55]In our benchmark scenario, we assume that the same predistribution-focused pattern will prevail in the future as in the past, namely the decline in pretax inequality will be similar in magnitude to posttax inequality decline over the 2026-2100 period. See Bothe et al, 2026, Fig. 22a-22b. However, this has no impact for our global income tax simulations, which only depend on post-tax income distributions.

We are now in a position to analyze the structure of winners and losers from the Global Justice Platform, both in comparison with 2025 monetary incomes and with alternative 2026-2100 development scenarios. Our main conclusion is that the vast majority of the population – about 95-98% in the Global South and 85-95% in the Global North – benefits from the GJP, but with large variations across countries and scenarios, potentially implying fierce political opposition from beyond just the ultra-rich [56]In order to study these questions, we analysed fully integrated income and wealth distributions for g-percentiles for all world regions. See Bothe et al. (2026) for further results.
 
We start with a comparison with the monetary incomes of 2025 (Figure 2.17). At the global level, about 89% of the population sees their annual monetary income more than double between 2025 and 2100, while less than 2% experience an income decline. In the poorer regions (Sub-Saharan Africa, South & South-East Asia, Middle East/North Africa), about 99% of the population experiences a more than 100% increase in monetary income, with virtually no income decline. In the richer regions, by contrast, the share of the population gaining more than 100% drops to about 45% in North America/Oceania and 28% in Europe, while a significant minority experiences a monetary income decline (about 14% of the population in North America/Oceania and 6% in Europe).

It should be stressed that the segments experiencing an income decline correspond essentially to the top of the income distribution within each region. The vast majority of the population in rich countries – including the entire bottom and middle of the distribution, who also benefit from country dividends through better-funded education and health systems and from the compression of the income scale – clearly comes out ahead. It is crucial to note that these material benefits would be in addition to important non-monetary benefits associated with increasing leisure hours, limiting global warming, financing the energy transition, and curbing the destabilizing effects of extreme inequality. If we include estimates for the value of leisure, then we find that over 99% of the population is better off in 2100 than in 2025, including in the richest regions [57]See Bothe et al, 2026, Figure 36b. It should be noted, however, that some of the monetary losers – who make up sizeable minorities in North America/Oceania and Europe – might not share ex ante these valuations of extra leisure time.
 
We have also run similar simulations using wealth (rather than income) [58]See Bothe et al, 2026, Figure 38 and Appendix Figure O5b. We have run simulations for private wealth and for augmented wealth (including the private value of public wealth), as well as numerous simulations with varying magnitudes of compression of income inequality between 2025 and 2100. In our benchmark scenario, the income scale is compressed to 1 to 5 by 2100. If we compress the scale even further, say 1 to 3 or 1 to 4 rather than 1 to 5, then we find larger income gains for the bottom 80% of the population (and potentially stronger political support), but a larger fraction of losers at the top. Conversely, if the compress the scale less intensively, say 1 to 8 or 1 to 12 or 1 to 15 rather than 1 to 5, then we reduce the share of losers at the top, but at the expense of very small (or in some cases negative) income gains for the bottom 80%, which is maybe not a very promising road to follow from a political viewpoint. To summarize, the 1 to 5 scale appears to be a good compromise in order to generate large gains for the bottom 80% while limiting the share of losers at the top [59]See Bothe et al, 2026, Appendix Figures P1a-P1j.
 
We now move to the comparison with alternative 2026-2100 development scenarios, namely the “Productivist Convergence” (PC) and “Persistent Inequality” (PI) scenarios analyzed in Chapter 1. We assume that both PC and PI scenarios follow an “Intermediate Decarbonization” trajectory, which corresponds approximately to current country pledges (an optimistic assumption). This leads to a temperature rise of around 4.2°C by 2100, compared with 1.8°C under “Sustainable Convergence” (SC). If we instead assume that the PC and PI scenarios follow a “Slow Decarbonization” trajectory (which roughly corresponds to current policies), the temperature rise would be as high as 4.8°C, thereby worsening the case for these alternative scenarios.
 
We start with a comparison against the PI scenario. If we only compare monetary incomes, i.e. if we do not value in any way the extra free time (leisure) nor the preservation of planetary habitability associated with the SC scenario, then by construction the comparison looks very good for the PI scenario, especially in rich countries, but also in many middle-income countries. In Europe, 96% of the population has a higher monetary income under the PI scenario than under the SC scenario; in North America/Oceania, the corresponding figure is 88%; at the world level, it is as high as 42% [60]See Bothe et al, 2026, Figure 39a. In the PI and PC scenarios, we assume that each country keeps the same level of post-tax income inequality between 2025 and 2100. At the same time, if we introduce what we consider to be plausible estimates for the valuation of free time (leisure) and planetary habitability [61]See Chancel et al, 2026, Section 7 and appendix D for a detailed discussion of how we value free time and planetary habitability (including well-being and GDP losses) in our benchmark estimates. These are lower-bound estimates in the sense that we assume linear effects with respect to temperature rise and neglect entirely the issue on non-linearities and cataclysmic tipping points, which are very likely to happen if temperature rises gets above 2.5-3.5° C. Also, we assume that PI and PC scenarios come with ID trajectories, but at this stage it looks as if we are closer to SD trajectory, implying a larger temperature rise than we assume in our benchmark computations (4.8°C rather than 4.2°C), then the situation changes completely: the fraction of the population favoring our Sustainable Convergence scenario over the persistent inequality scenario jumps from 4% to 83% in Europe, from 12% to 89% in North America/Oceania and from 58% to 95% at the world level (Figure 2.18a).
 

We obtain similar conclusions when comparing against the PC scenario (Figure 2.18b). The main difference is that the PC scenario is slightly less favourable than the PI scenario for the richest countries (from the viewpoint of monetary income), so that even larger majorities prefer the SC scenario after the valuation of free time and planetary habitability is taken into account.  

We draw several conclusions from these results. Generally speaking, the Global Justice Platform – or similar policy platforms – is likely to face fierce political opposition from significant fractions of the population in the Global North (and not just the ultra-rich in the Global North and the Global South) and will require very strong collective mobilization from lower- and middle-income classes to be adopted and implemented. The ultra-rich are obviously the main losers of the GJP in all countries, but much larger segments of the population – typically 5-10% of the population in the South and up to 10-20% of the population of the North – are on the brink of losing out from the GJP, especially if they do not place a high value on free time and planetary habitability. If the ultra-rich can convince these segments of the population that free time and planetary habitability have limited value, and reach even broader segments of the population with a similar message, then a platform like the GJP has little chance of being adopted. In other words, the key cultural and intellectual battle is not only about reducing inequality and taxing billionaires and multimillionaires: it is also about valuing sufficiency, free time and planetary habitability as such. This can only be achieved with the help of a broad citizen coalition documenting the value of sufficiency (including the shift to immaterial consumption, changes in food habits, and implied reforestation) and the damages of a large temperature rise and broader biodiversity loss. We will return to this discussion of political strategies in Chapter 4.