Conflict and Development

(with Joan Esteban) Annual Reviews of Economics  9, 263-293, 2017.

Summary. In this review, we examine the links between economic development and social conflict. By economic development, we refer broadly to aggregate changes in per capita income and wealth or in the distribution of that wealth. By social conflict, we refer to within-country unrest, ranging from peaceful demonstrations, processions, and strikes to violent riots and civil war. We organize our review by critically examining three common perceptions: that conflict declines with ongoing economic growth; that conflict is principally organized along economic differences rather than similarities; and that conflict, most especially in developing countries, is driven by ethnic motives.

Aspirations and Inequality

(with Garance Genicot) Econometrica 85, 485-519, 2017. Online Appendix. 2009 version.

Summary. This paper develops a theory of socially determined aspirations, and the interaction of those aspirations with growth and inequality. The interaction is bidirectional: economy-wide outcomes determine individual aspirations, which in turn determine investment incentives and social outcomes. Thus aspirations, income, and the distribution of income evolve jointly.

Kenneth Arrow

El Trimestre Económico 84. 761-769, 2017.

Summary. A translation into Spanish of my post on the event of Kenneth Arrow’s death. The original post is available here.

Information and Enforcement in Informal Credit Markets

(with Parikshit Ghosh), Economica 83, 59–90, 2016.

Summary. We study loan enforcement in informal credit markets with multiple lenders but no sharing of credit histories, and derive the dynamics of loan size and interest rates for relational lending. In the presence of a sufficient fraction of ‘natural defaulters’, the rest of the market can be incentivized against default by micro-rationing—sharper credit limits and possibly higher interest rates that serve as gateways into new borrowing relationships. When there are too few natural defaulters in the market, this can be supplemented by macro-rationing—random exclusion of some borrowers. When information collection is endogenized, multiple equilibria may arise. (Published version of unpublished notes from 2001.)

Aspirations And The Development Treadmill

Journal of Human Development and Capabilities 17, 309–323, 2016.

Summary. I describe a positive theory of socially determined aspirations, and some implications of that theory for the study of economic inequality and social conflict. The main contribution of the theory is that it attempts to describe, in the same explanatory arc, how a change in aspirations can be inspirational in some circumstances, or a source of frustration and resentment in others. These different reactions arise from the aspirational gap: the difference between socially generated aspirations and the current socio-economic standard that the individual enjoys. Ever-accelerating economic development can cut both ways in terms of inspiration and frustration.

Anatomy of a Contract Change

with Rajshri Jayaraman and Francis de Vericourt, American Economic Review 106, 316-358, 2016. Online Appendix.

Summary. We study a contract change for tea pluckers. Base wages increased while incentive piece rates were lowered or kept unchanged. Yet, in the following month, output increased by 20–80%. This response contradicts the standard model, is only partly explicable by greater supervision, and appears to be “behavioral.” But in subsequent months, the increase is comprehensively reversed. Our findings suggest that behavioral responses may be ephemeral, and should ideally be tracked over an extended period. 

Poverty and Self-Control

(with Doug Bernheim and Sevin Yeltekin), Econometrica 83 (5), 1877-1911, 2015. Online Appendix. A link to the 1999 version, which only had numerical results.

Summary. Poverty can perpetuate itself by undermining the capacity for self-control.  Our main result demonstrates that low initial assets can limit self-control, trapping people in poverty, while those with high initial assets can accumulate indefinitely.

 

Nit-Piketty

CesIfo Economic Studies 2015.

Summary. Yes, capital must displace labor, but not because r > g. This article is based on this blog post, Branko Milanovic objected here; I replied. Piketty replies to some of his critics here.

 

The Farsighted Stable Set

(with Rajiv Vohra), Econometrica  83, 977–1011, 2015. Online Appendix.

Summary. We propose a definition of farsighted stability in coalitional games, in the spirit of von Neumann-Morgenstern stability and its modification by Harsanyi. We provide a necessary and sufficient condition for the existence of a farsighted stable set containing just a single-payoff allocation. We then conduct a comprehensive analysis of the existence and structure of farsighted stable sets in simple games.

Coalition Formation

(with Rajiv Vohra),  in Handbook of Game Theory Vol 4 (H.P. Young and S. Zamir, eds), Elsevier North Holland, 2014.

Summary. This chapter surveys a sizable and growing literature on coalition formation. We refer to theories in which one or more groups of agents (“coalitions”) deliberately get together to jointly determine within-group actions, while interacting noncooperatively across groups. The chapter describes a variety of solution concepts, using an umbrella model that adopts an explicit real-time approach. Players band together, perhaps disband later and re-form in shifting alliances, all the while receiving payoffs at each date according to the coalition structure prevailing at the time. We use this model to nest two broad approaches to coalition formation, one based on cooperative game theory, the other based on noncooperative bargaining. Three themes that receive explicit emphasis are agent farsightedness, the description of equilibrium coalition structures, and the efficiency implications of the various theories.