If I were the social planner, the next Nobel Prize in Economics would be awarded to Samuel Bowles, Glenn Loury, and John Roemer (as I wrote last year). Their work is foundational to the modern study of inequality, addressing normative and positive dimensions with profound insight.
Bowles has made so many contributions to the study of inequality it is hard to summarize them. His work on contested exchange, which places power imperfect information at the center of labor market equilibrium, was decades ahead of the modern focus on monopsony and has been a foundational challenge to classical human capital theory. Sam was equally farseeing in his work on identity and the totality of personality/worldview as determining outcomes of workers. As such, he raised issues of identity far before others. He has been integral in addressing the determinants of intergenerational mobility, addressing (and concluding it was second order) the role of genes in inequality.
Glenn Loury has deeply transformed our understanding intergenerational mobility and racial inequality. Three stand out. His model of family investment and intergenerational mobility (developed independently from Becker and Tomes) remains the workhorse model of intergenerational mobility. His integration of social capital into intergenerational mobility models provided essential insights in the ways that nonconvexities can produce multiple steady states for communities starting at different initial conditions. His work with Stephen Coate on remains the foundation of the theory of affirmative action and incentives. His work on stigma and spoiled identity has profound implications for persistent racial inequality; in my opinion Glenn's The Anatomy of Racial Inequality is profound and underappreciated.
John Roemer has made essential contributions to both philosophy and economics. In philosophy, he pioneered the idea of responsibility-sensitive egalitarianism as a foundation for understanding equality of opportunity. As such, John's work represents a major challenge to Rawlsian ideas of justice. This work has also led to important empirical work that has reformulated measures of intergenerational persistence via metrics for inherited inequality. In economics, he has done foundational work on developing rigorous formulations of Marxian economics (one especially important example is his reformulation of the idea of exploitation), the interactions of inequality and electoral outcomes, and Kantian equilibrium with attendant implications for intra and intergroup inequality.