Is inequality harmful for growth? We suggest that it is. To summarize our main argument: in a society where distributional conflict is more important, political decisions are more likely to produce economic policies that allow private individuals to appropriate less of the returns to growth promoting activities, such as accumulation of capital and productive knowledge. In the paper we first formulate a theoretical model that formally captures this idea. The model has a politico-economic equilibrium, which determines a sequence of growth rates depending on structural parameters, political institutions, and initial conditions. We then confront the testable empirical implications with two sets of data. A first data set pools historical evidence-which goes back to the mid 19th century-from the US and eight European countries. A second data set contains post-war evidence from a broad cross-section of developed and less developed countries. In both samples we find a statistically significant and quantitatively important negative relation between inequality and growth. After a comprehensive sensitivity analysis, we conclude that our findings are not distorted by measurement error, reverse causation, hetroskedasticity, or other econometric problems.

Essays exploring the relationship between economic growth and inequality and the implications for policy makers.

We posit that the relationship between income inequality and economic growth is mediated by the level of equality of opportunity, which we identify with intergenerational mobility. In economies characterized by intergenerational rigidities, an increase in income inequality has persistent effects—for example by hindering human capital accumulation— thereby retarding future growth disproportionately. We use several recently developed internationally comparable measures of intergenerational mobility to confirm that the negative impact of income inequality on growth is higher the lower is intergenerational mobility. Our results suggest that omitting intergenerational mobility leads to misspecification, shedding light on why the empirical literature on income inequality and growth has been so inconclusive.

Is there a tradeoff between raising growth and reducing inequality and poverty? This paper reviews the theoretical and empirical literature on the complex links between growth, inequality, and poverty, with causation going in both directions. The evidence suggests that growth can be effective in reducing poverty, but its impact on inequality is ambiguous and depends on the underlying sources of growth. The impact of poverty and inequality on growth is likewise ambiguous, as several channels mediate the relationship. But most plausible mechanisms suggest that poverty and inequality reduce growth, at least in the long run. Policies play a role in shaping these relationships and those designed to improve equality of opportunity can simultaneously improve inclusiveness and growth.

The Fund has recognized in recent years that one cannot separate issues of economic growth and stability on one hand and equality on the other. Indeed, there is a strong case for considering inequality and an inability to sustain economic growth as two sides of the same coin. Central to the Fund’s mandate is providing advice that will enable members’ economies to grow on a sustained basis. But the Fund has rightly been cautious about recommending the use of redistributive policies given that such policies may themselves undercut economic efficiency and the prospects for sustained growth (the so-called “leaky bucket” hypothesis written about by the famous Yale economist Arthur Okun in the 1970s). This SDN follows up the previous SDN on inequality and growth by focusing on the role of redistribution. It finds that, from the perspective of the best available macroeconomic data, there is not a lot of evidence that redistribution has in fact undercut economic growth (except in extreme cases). One should be careful not to assume therefore—as Okun and others have—that there is a big tradeoff between redistribution and growth. The best available macroeconomic data do not support such a conclusion.

One side in the current debate about who benefits from growth has focused solely on average impacts on poverty and inequality, while the other side has focused on the diverse welfare impacts found beneath the averages. Both sides have a point.

Eight papers, both theoretical and applied, on the concept of equality of opportunity which says that a society should guarantee its members equal access to advantage regardless of their circumstances, while holding them responsible for turning that access into actual advantage by the application of effort.