three large countries, namely lower middle‐income India; upper middle‐income Brazil; and high‐ income United States. The poorest 40% of the populations in these three countries enjoy very different income levels; the mean income for that group in Brazil is equivalent to the ninth decile in India, roughly, and an analogous comparison holds between the United States and Brazil. Whereas the annual mean income among the poorest 40% of US citizens is $8,861 (in 2011 PPP), it is $1,819 in Brazil, and $664 in India – about 13 times less than in the richer country.<sup>13</sup> Our summary description of shared prosperity trends focuses on the 2008‐2013 period, and draws on a World Bank data set known as the Global Shared Prosperity Database (GSPD). This data set consists of growth spells for the income or consumption aggregate for the bottom 40% and for the mean, obtained from intertemporally comparable national household surveys. A first round of data included spells circa 2006‐11 and was described in World Bank (2015a) and World Bank (2015b). The second and third rounds focused on spells circa 2007‐12 and 2008‐13 and were reported in World Bank (2016a and 2016b).

The latest available wave of the GSPD covers 83 countries and provides these two annualized growth rates (for the bottom 40% and the overall mean) for a five‐year period circa 2008‐13.<sup>14</sup> Though this sample includes fewer than half of the world’s countries, it does nevertheless cover 75% of the world’s population in 2013. The geographical coverage across regions is unbalanced: of these 83 countries, 24 belong to one single region, Eastern Europe and Central Asia (EECA), while Industrialized countries and Latin America and the Caribbean (LAC) follow in the regional contribution to the sample with 20 and 16 countries, respectively. The sample coverage also differs across regions in terms of population. At the high end, coverage is 94% for East Asia and Pacific (EAP) and 89% for EECA. The coverage rates in the South Asia region (SAR) and LAC are somewhat lower at 87% and 86%, respectively, while the database covers a significantly lower proportion of the population in the Middle East and North Africa region (MENA) ‐ 32% ‐ and Sub‐Saharan Africa (SSA) ‐ 23%.

Growth rates for the bottom 40% and for the overall mean are shown in figure 2. During 2008‐2013, ��� was positive in only 8 of the 20 industrialized countries. In sharp contrast, however, in all other regions most countries had positive growth rates for the bottom 40%. In fact, that is the case for all countries in Asia (EAP and SAR). Overall, 60 countries ‐ representing 72% of the sample ‐ experienced positive average income growth for the bottom 40%. In terms of population, this means that 89% of the population captured by the GSPD (67% of the world’s population) lived in countries where the bottom 40% saw their incomes grow during the period circa 2008‐13.

> 13 An immediate consequence of this heterogeneity in absolute income levels among people in the bottom 40% across different countries is that the group of people on whom the shared prosperity goal focuses is not the same group as the extreme poor globally. Indeed, in the poorest countries (like Togo or the Democratic Republic of Congo), the incidence of extreme poverty (at $1.90/day) exceeds 40%, whereas in richer countries, such as Thailand or the Russian Federation, that incidence is close to zero.

> 14 As noted in World Bank (2016b), “growth rates are computed as annualized average growth rates in per capita real household income (or consumption) over a five‐year period roughly circa 2008–13, where only those countries with surveys that meet the following criteria are included: for the latest household survey year for a country (T1), the most recent survey available between 2011 and 2015 is used. Only surveys collected between three and seven years before the most recent survey are considered for the earlier survey (T0), and of those, the one nearest year T1 – 5 is selected.”

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