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.

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.

Even minute increases in a country's growth rate can result in dramatic changes in living standards over just one generation. The benefits of growth, however, may not be shared equally. Some may gain less than others, and a fraction of the population may actually be disadvantaged. Recent economic research has found both positive and negative relationships between growth and inequality across nations. The questions raised by these results include: What is the impact on inequality of policies designed to foster growth? Does inequality by itself facilitate or detract from economic growth, and does it amplify or diminish policy effectiveness? This book provides a forum for economists to examine the theoretical, empirical, and policy issues involved in the relationship between growth and inequality. The aim is to develop a framework for determining the role of public policy in enhancing both growth and equality. The diverse range of topics, examined in both developed and developing countries, includes natural resources, taxation, fertility, redistribution, technological change, transition, labor markets, and education. A theme common to all the essays is the importance of education in reducing inequality and increasing growth.

This paper shows that growth and income distribution dynamics are closely linked through occupation, financial intermediation, and education. We use the micro data from Thailand for 1976-1996. The compositional changes across these characteristics account for half of the Thai inequality increase and forty percent of the Thai growth and poverty reduction. Financial deepening and educational expansion contributed to increasing inequality while occupational transformation contributed to poverty alleviation. The changes in income gaps across the income-status groups, that is, divergence and then convergence, give rise to inverted-U inequality dynamics. These two growth-related components of inequality dynamics, composition and income-gap dynamics, explain virtually all the change in overall inequality, except its initial rise. Thus, inequality dynamics can be viewed as integral part of wider process of growth as Kuznets speculated.

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.

This paper analyzes the extent of income inequality from a global perspective, its drivers, and what to do about it. The drivers of inequality vary widely amongst countries, with some common drivers being the skill premium associated with technical change and globalization, weakening protection for labor, and lack of financial inclusion in developing countries. We find that increasing the income share of the poor and the middle class actually increases growth while a rising income share of the top 20 percent results in lower growth—that is, when the rich get richer, benefits do not trickle down. This suggests that policies need to be country specific but should focus on raising the income share of the poor, and ensuring there is no hollowing out of the middle class. To tackle inequality, financial inclusion is imperative in emerging and developing countries while in advanced economies, policies should focus on raising human capital and skills and making tax systems more progressive.

The relationship between growth, inequality, and poverty lies at the heart of development economics. This volume draws together many of the most important recent contributions to the controversies surrounding this topic. Some of the chapters help explain why there is profound disagreement on crucial issues of growth, poverty and inequality within academic circles, and among organizations and various groups active in the development field. Another central theme is the cross-country evidence on the relationship between growth and poverty, and the extent to which it is valid to draw policy conclusions from this empirical evidence. The volume also shows how new microeconomic techniques such as poverty maps and microsimulation models can be used to improve poverty analysis and the design of pro-poor policies. The overall conclusion points to the need for diverse strategies towards growth and poverty, rather than simple blanket policy rules. Initial conditions, specific country structures, and time horizons all play a significant role. Initial conditions affect the speed with which growth reduces poverty and can also determine whether policies such as trade liberalization have a pro-poor or an anti-poor outcome. Improved education is valuable in itself, and also contributes to poverty reduction; but its effect on inequality depends on supply and demand factors, which differ significantly across countries. Likewise, the quantitative impact on poverty of redistribution from the rich to the poor vis-à-vis an increase in total national income can vary greatly across countries. Hence the need for creative approaches to poverty which take full account of the specific circumstances of individual nations and which assign a central role to inequality analysis in the discussion of poverty-alleviation policies.