Global inequality: How large is the effect of top incomes?

In this paper, we estimate the recent evolution of global interpersonal inequality and examine the effect of omitted top incomes on the level and direction of global inequality. We propose a methodology to estimate the truncation point of household surveys by combining information on income shares from household surveys and top income shares from tax data. The methodology relies on a flexible parametric functional form that models the income distribution for each country-year point under different assumptions on the omitted information at the right tail of the distribution. Goodness-of-fit results show a robust performance of our model, supporting the reliability of our estimates. Overall, we find that the undersampling of the richest individuals in household surveys generate a downward bias in global inequality estimates that ranges between 15 per cent and 42 per cent, depending on the period of analysis, and the assumed level of truncation of the income distribution

Global inequality: How large is the effect of top incomes?

Despite the growing interest in global inequality, assessing inequality trends is a major challenge because individual data on income or consumption is not often available. Nevertheless, the periodic release of certain summary statistics of the income distribution has become increasingly common. Hence, grouped data in form of income shares have been conventionally used to construct inequality trends based on lower bound approximations of inequality measures. This approach introduces two potential sources of measurement error: first, these estimates are constructed under the assumption of equality of incomes within income shares; second, the highest income earners are not included in the household surveys from which grouped data is obtained. In this paper, we propose to deploy a flexible parametric model, which addresses these two issues in order to obtain a reliable representation of the income distribution and accurate estimates of inequality measures. This methodology is used to estimate the recent evolution of global interpersonal inequality from 1990 to 2015 and to examine the effect of survey under-coverage of top incomes on the level and direction of global inequality. Overall, we find that item non-response at the top of the distribution substantially biases global inequality estimates, but, more importantly, it might also affect the direction of the trends

An open database on inequality and polarization in length of life (1950–2021)

However, this measure is simply the mean of the distribution of the length of life and, as such, neglects individual disparities in health outcomes. Tracking the evolution of lifespan inequality is essential to promoting social justice and equity by identifying and addressing the root causes of these disparities. In this paper, we use life tables from the UN World Population Prospects to develop the most comprehensive database of lifespan inequality and polarization for 258 countries and areas for the period 1950–2021. Monitoring health is key for identifying priorities in public health planning and improving healthcare services. Life expectancy has conventionally been regarded as a valuable indicator to compare the health status of different populations. To help with the visualization and the use of these estimates, we have designed a user-friendly website that enables users to compute lifespan inequality for any group of countries of their choice. These extensive series on the distribution of lifespans provide access to crucial information for researchers, policy-makers, and the general public, thus representing a fundamental step towards a better understanding of health differences within and between nations

The Lifespan Disparity Dataset: An open repository on inequality and polarization in length of life (1950–2021)

Monitoring health is key for identifying priorities in public health planning and improving healthcare services. Life expectancy has conventionally been regarded as a valuable indicator to compare the health status of different populations. However, this measure is simply the mean of the distribution of the length of life and, as such, neglects individual disparities in health outcomes. In this paper, we use life tables from the UN World Population Prospects to develop the most comprehensive dataset of lifespan inequality and polarization for 258 countries and areas for the period 1950–2021. These extensive series on lifespan distributions provide access to crucial information for researchers, practitioners, and the general public, thus contributing to a better understanding of health differences within and between nations

Global income polarization: Relative and absolute perspectives

This paper presents the first global and regional estimates of polarization and bipolarization spanning the period 1960–2020. The study relies on group data to implement a flexible parametric model to obtain the global income distribution and polarization estimates. The study introduces a battery of sensitivity tests to assess the reliability of polarization estimates under various assumptions, with particular emphasis on the impact of survey under-coverage of top incomes on global polarization levels and trends. Overall, we find that relative bipolarization has consistently decreased since 1980, while in absolute terms it has increased since 1960. The more general measure of relative polarization has also exhibited a steady decline since 1980; however, the trend in its absolute counterpart depends on the size of a sensitivity parameter, which reflects whether individuals cluster with peers of similar income or are segregated from different income groups. Consequently, absolute polarization declined over time for lower values of this parameter but increased for higher values

The Lifespan Disparity Dataset (LDD): An open repository on inequality and polarization in length of life (1950-2021)

This database includes a comprehensive set of estimates on lifespan inequality and polarization for 258 countries and areas for the period 1950–2021. These extensive series on the distribution of lifespans provide access to crucial information for researchers, policy-makers, and the general public, thus representing a fundamental step towards a better understanding of health differences within and between nations

An open database on inequality and polarization in length of life (1950-2021)

This database includes a comprehensive set of estimates on lifespan inequality and polarization for 258 countries and areas for the period 1950–2021. These extensive series on the distribution of lifespans provide access to crucial information for researchers, policy-makers, and the general public, thus representing a fundamental step towards a better understanding of health differences within and between nations.</p