# **Introduction**

This essay aims to complement Thomas Piketty’s analysis in _Capital in the 21_<sup>_st_</sup> _Century_ (C21) by offering a twofold global perspective on inequality. First, I review the trends in global inequality, defined as the inequality among all persons in the world regardless of their country of residence. Piketty’s analysis, like most perspectives on inequality, concentrates on inequality among individuals _within_ a country. Adopting a global (or cosmopolitan) perspective on inequality sheds light on another aspect of the world we live in. While no world government exists, international organizations play an increasing role, and the cosmopolitan view is the only one consistent with their mandates. Globalization has coincided with rapid growth in some of the poorest countries on the one hand, and increasing inequality in many of these same countries on the other hand. Global inequality captures the overall effect of these forces on persons irrespective of where they might be living. Second, I summarize the developments in within-country inequality in the developing world. This flows naturally from an analysis of the global distribution, which can be broken up into differences between and within countries. An analysis of global inequality needs to separate the recognition of inequality from the capacity to reduce it, which largely remains at the countrylevel (Anand and Segal, 2015).

C21 documents a stark rise in inequality within developed economies in North America and Western Europe. Emerging economies do not feature prominently in the empirical work nor do they have an explicit role in the model. Milanovic (2014) argues that in Piketty’s model, developed countries today are what developing economies will look like in the future. For example, China today is a wealth-young economy, similar to the US in the 19<sup>th</sup> century, but given China’s fast demographic transition, it may be quite similar to today’s France in fifty years. So the transition path is very much the same, just at a much faster pace. Furthermore, Milanovic notes that emerging economies also affect C21’s inequality ���. On the one hand, given their lower capital stock, emerging markets continue to offer higher returns, pushing up �, which Piketty recognizes as one of the mechanisms behind the apparent stability in �. On the other hand, their higher growth rates push up � thus delaying the point at which ��� materializes.

Although Piketty’s model deals almost exclusively with developed Western nations, this has not stopped the book from achieving a global appeal. C21 has been widely translated, including into Chinese, Japanese and Korean, and reported in the local press (Brasor, 2015; Denney, 2014). More generally, the concern with inequality goes beyond the developed countries. For example, in a survey of 15 developing countries, 77% of policy makers recognize that the current level of inequality threatens long-term development, while only 7% see inequality as conducive to longterm development (UNDP, 2014). Similarly, in a survey of more than 500 policy makers in Asia, 70% suggest that the concern with income inequality increased in the last 10 years, while just over half disagreed that higher income inequality is acceptable as long as poverty is falling (Kanbur and Zhuang, 2012).

A word of caution is needed right from the beginning. Expanding the analysis to a global level faces formidable data constraints. Due to the unavailability of administrative data for developing 2