Incomes in the poorest two quintiles on average increase at the same rate as overall average incomes, according to a new working paper by David Dollar (Brookings Institution), Tatjana Kleineberg and Aart Kraay. In a global dataset spanning 118 countries over the past four decades, changes in the share of income of the poorest quintiles are generally small and uncorrelated with changes in average income. The variation in changes in quintile shares is also small relative to the variation in growth in average incomes, implying that the latter accounts for most of the variation in income growth in the poorest quintiles. These findings hold across most regions and time periods, as well as conditional on a variety of country-level factors that may matter for growth and inequality changes. This evidence confirms the central importance of economic growth for poverty reduction and illustrates the difficulty of identifying specific macroeconomic policies that are significantly associated with the relative growth rates of those in the poorest quintiles. This reprise of Dollar and Kraay's earlier work also looks at the World Bank's new "shared prosperity " goal by considering the income growth rates of the poorest 40% of the population in each country in addition to looking at the poorest 20%.