Income Distribution: Effects on Growth and Development

I review the literature on the effects of inequality on growth and development in the developing world. Two stylized facts emerge from empirical studies: inequality is more likely to harm growth in countries at low levels of income (below about $3200 per capita in 2000 dollars); and it is at high levels of inequality (at or above a Gini coefficient of .45) that a negative association emerges. Between 15 and 40 percent of the developing world's population lives in countries with these characteristics, depending on the inclusion of China, whose level of inequality has recently been measured at almost .45. Theory and evidence suggest that high inequality affects growth: (1) through interaction with incomplete and underdeveloped markets for capital and information; (2) by discouraging the evolution of the economic and political institutions associated with accountable government (which in turn enable a market environment conducive to investment and growth); and (3) by undermining the civic and social life that sustains effective collective decision-making.