Increasing inequality demands action. The richest 10% of adults globally receives more than half (53%) of the world’s income, whereas the poorest half receives 8%. Wealth is even more concentrated, with the richest 10% owning around three-quarters of global wealth while the poorest half owns just 2%¹. Almost two-thirds of people live in countries where inequality is rising².

The consequences are well established. A growing body of research links higher income inequality to lower social mobility, poorer health outcomes and slower economic growth. Unequal access to education, health care, housing and finance shapes the opportunities that direct people’s lives.

Why are rich people so pessimistic? What the numbers say

Yet, all this knowledge has not produced a policy response. One reason is political: inequalities create powerful beneficiaries. Another is practical: a gap between science and policy remains to be filled. Evidence on inequality is dispersed across disciplines and institutions. Research on policy effectiveness — showing what has worked, in which contexts and through which mechanisms — is insufficiently synthesized and often inaccessible.

What’s needed is an independent scientific body mirroring the Intergovernmental Panel on Climate Change (IPCC). This would periodically and systematically assess evidence on the scale, nature, drivers and consequences of inequality. It would also evaluate evidence on policies and synthesize the conclusions from the successes and failures of different countries.

In 2025, we were asked by President Cyril Ramaphosa of South Africa to participate in the G20 Extraordinary Committee of Independent Experts on Global Inequality (chaired by J.E.S.). We presented a report³ to the G20 countries, in which our main recommendation was for their governments to establish an International Panel on Inequality (IPI).

Since then, a founding committee, of which we are also members, has begun to develop the proposal under the leadership of South Africa, Brazil, Spain and Norway. United Nations secretary-general António Guterres has endorsed the initiative, the African Union unanimously supports it and so do more than 600 economists and inequality experts. Here we outline that case.

Unequal opportunities

Researchers agree that the level of inequality is high globally, that wealth inequality is greater than income inequality and that both forms are getting worse worldwide. Of the US$280 trillion of new wealth created globally between 2000 and 2024, the top 1% gleaned 41% while the bottom 50% got less than 1%³.

Inequality can be measured in relative or absolute terms. Relative measures, expressed as a proportion of the total, are often represented using the Gini coefficient, on a scale from 0 to 1. If everyone earns the same income or has the same wealth, the score is 0; if one person gets everything, the score is 1. The World Bank defines high income inequality as anything more than 0.4.

Globally speaking, relative inequality is high, but it has declined from 0.69 in 1990 to 0.60 in 2022², mainly because of rapid income growth in China and other parts of Asia (see ‘Disparities between rich and poor’).

Meanwhile, relative inequality in most countries has risen since 1990 and disparities persist between regions. Gini coefficients are highest in Sub-Saharan Africa (0.54 in 2022) and Latin America and the Caribbean (0.47), and lowest in Europe and Central Asia (0.32)². However, even in historically more-equal countries, such as Nordic nations, inequality is on the rise.

Inequality can also be expressed in terms of purchasing power, as absolute inequality. If everyone’s incomes increase by the same percentage, say 5%, relative inequality will be unchanged but absolute inequality — the dollar value of the difference — will rise.

Why the world cannot afford the rich

By that measure, the gap between individuals is widening globally. Between 2000 and 2024, the average wealth of the bottom half of the global population grew by only $585, while the average wealth of the richest 1% went up by $1.3 million³.

What does that mean for people’s lives? In Kenya, a boy or girl from a rich family has a one in two chance of continuing education beyond secondary school, whereas for a poor family, a boy has a one in 40 chance and a girl has a one in 100 chance of doing so³. Countries with higher inequality are seven times more likely to experience democratic erosion — undermining of checks and balances, restriction of civil rights, manipulation of elections and introduction of authoritarian practices — than are those with lower inequality³.

There is sufficient consensus on these broad conclusions to justify urgent actions. But to undertake the right ones, policymakers and researchers must have better and more reliable data and a greater understanding of the processes that create inequality and their consequences.

The IPI would address four areas: the measurement of inequality; its drivers; its consequences; and the policies that are available to address it.

Disparities in measurements

Consensus on the broad picture must not be confused with consensus on all aspects of the data. Household surveys remain the main source for data on inequality and poverty, but these tend to under-record incomes at the top, because the richest people tend not to respond to surveys. Thus, standard approaches underestimate the scale of inequality.

Methods have been developed to try to correct for this bias, by supplementing surveys with data from tax, administrative and national accounts. These approaches weigh up data sources in different ways and make varying assumptions about missing information — so can give markedly different answers.

Why we need to measure people’s well-being — lessons from a global survey

For example, in 2022, India’s Gini coefficient was variously estimated as 0.25 by the World Bank⁴, 0.49 by the United Nations University World Institute for Development Economics Research (UNU-WIDER) in Helsinki² and 0.64 by the World Inequality Lab⁵. It is impossible to base policies on such statistics alone, which describe India as being both one of the least unequal countries (better than Sweden) and one of the most unequal. Policymakers would also need to consider other data, such as the extent of poverty and malnutrition and the number of billionaires.

The IPI could help by clarifying the strengths and limitations of different approaches, to improve the measurement of inequality. It could explain why estimates and trends diverge, identify findings that are robust across methods, clarify how to combine complementary measures and encourage greater transparency, harmonization and standardization. For example, governments need a standardized way of augmenting survey data to present a more accurate picture of inequality levels and top incomes.

Wealth inequality deserves special attention. Wealth is linked to power and influence, and inherited wealth perpetuates inequality across generations. Wealth inequality is generally more pronounced than income inequality, yet wealth data are weaker. Globally, income from wealth remains highly concentrated, with a Gini of 0.94, and 80% of the world’s population receives zero or near-zero income from wealth⁶. Assets are often hidden, under-reported or difficult to value, and comparable administrative and tax data are unavailable in many countries.

The IPI could bolster efforts worldwide to improve data on wealth inequality through analyses of inheritance and other tax data, for example, and could help governments to develop tools to do this.

Understanding causes

When it comes to the drivers of inequality in incomes, the nature and scale of taxes and transfer payments from the state to citizens (such as through welfare systems) have a big effect. But so do other factors that determine the market distribution of income, such as employment, wage-setting and access to education and health care.

Income inequality can be exacerbated by differing access to well-paying jobs or ownership of assets that produce income. Increases in disparity might result from shifts in the economy, such as moving from a manufacturing to a service-sector economy or the weakening of unions. In many countries, the growth of corporate and financial market power has been associated with an increase in inequality.

Similarly, inequalities in wealth have been traced, in part, to reductions in taxes on earnings from investments or capital assets and to increases in intergenerational transmission of wealth⁷. Using data from the GC Wealth Project, our committee identified accumulated and inherited wealth as a key driver that entrenches inequality and undermines social mobility, fairness and opportunity for low-income populations. With an estimated $70 trillion expected to be passed down to heirs over the next decade³, it is likely that more countries will be characterized by a plutocracy that has inherited its wealth.

The IPI can have a key role in advancing understanding and reaching greater scientific consensus on the most important drivers of income and wealth inequality and why it is growing. It can also help to analyse the impact of challenges such as artificial intelligence and climate change on inequality.

Emerging technologies, especially AI, will alter demand for labour and further concentrate the yields to capital, intellectual property and data. Climate change is already imposing the greatest losses on populations that have the fewest resources to adapt, and the transition to a low-carbon economy will shape employment, prices, public revenue and asset ownership. Geopolitical conflicts, debt, trade rules and the architecture of international finance also affect inequality.

Tracking consequences

Inequality has economic, political and social consequences. A growing body of research links high levels of income inequality to weaker and less sustainable economic growth. Our report³ shows how policies aimed at reducing inequality can support stronger economic performance, contrary to long-standing assumptions. For instance, if the source of inequality is monopoly power, then policies that reduce monopoly power can reduce inequality and improve the economy.