Knowledge that Transforms

We show that it is impossible to achieve collusion in a duopoly when (a) goods are homogenous and firms compete in quantities; (b) new, noisy information arrives continuously, without sudden events; and (c) firms are able to respond to new information quickly. The result holds even if we allow for asymmetric equilibria or monetary transfers. The intuition is that the flexibility to respond quickly to new information unravels any collusive scheme. Our result applies to both a simple stationary model and a more complicated one, with prices following a mean-reverting Markov process, as well as to models of dynamic cooperation in many other settings.

We study a multisector model of growth with differences in TFP growth rates across sectors and derive sufficient conditions for the coexistence of structural change, characterized by sectoral labor reallocation and balanced aggregate growth. The conditions are weak restrictions on the utility and production functions. Along the balanced growth path, labor employed in the production of consumption goods gradually moves to the sector with the lowest TFP growth rate, until in the limit it is the only sector with nontrivial employment of this kind. The employment shares of intermediate and capital goods remain constant during the reallocation process.

This paper investigates how market structure affects efficiency and several dimensions of liquidity in an asset market. To this end, we generalize the search-theoretic model of financial intermediation of Darrell Duffie et al. (2005) to allow for entry of dealers and unrestricted asset holdings.

This paper examines the role of cash transfers as a screening device when combined with in-kind transfers. It shows that linking in-kind to cash transfers makes first-best redistribution possible despite the government's inability to tell rich and poor individuals apart. Moreover, the maximal attainable welfare for the poor can be pushed beyond its first-best level by distorting downward the quality of the indivisible good the poor receive relative to the cash value of their net transfers. Using in-kind transfers alone, as in Besley and Coate (1991), leads to a third-best solution.

We measure the welfare gain from removing aggregate consumption fluctuations in a model where each individual faces incomplete consumption insurance. We show that, because this welfare gain is a convex function of the overall consumption risk—aggregate plus idiosyncratic—each individual faces, to gauge the magnitude of the gain, it is important to match individuals' overall risk prior to any policy. In an economy calibrated to match individuals' overall risk, even removing 10 percent of aggregate fluctuations can result in a large welfare gain. Further, large gains do not necessarily depend on the countercyclical nature of idiosyncratic risk.

Community Size and Network Closure by Hunt Allcott, Dean Karlan, Markus M. Möbius, Tanya S. Rosenblat and Adam Szeidl. Published in volume 97, issue 2, pages 80-85 of American Economic Review, May 2007

We investigate the “generalized second-price” (GSP) auction, a new mechanism used by search engines to sell online advertising. Although GSP looks similar to the Vickrey-Clarke-Groves (VCG) mechanism, its properties are very different. Unlike the VCG mechanism, GSP generally does not have an equilibrium in dominant strategies, and truth-telling is not an equilibrium of GSP. To analyze the properties of GSP, we describe the generalized English auction that corresponds to GSP and show that it has a unique equilibrium. This is an ex post equilibrium, with the same payoffs to all players as the dominant strategy equilibrium of VCG.

Flavio Cunha; James Heckman.May, 2007.The technology of skill formation,Report,ChicagoAmerican Economic Association,17

Gender Differences in the Labor Market: Impact of IRCA by Catalina Amuedo-Dorantes, Cynthia Bansak and Steven Raphael. Published in volume 97, issue 2, pages 412-416 of American Economic Review, May 2007

This paper empirically examines belief updating of the perceived probability of arrest and its criminal deterrence effects using two longitudinal data sources. While beliefs about the probability of arrest are positively correlated with local official arrest rates, they are unresponsive to information acquired from random individuals and local neighborhood conditions. Importantly, perceptions respond to changes in an individual's criminal and arrest history. Young males who engage in crime without getting arrested revise their perceived probability of arrest downward, while those who are arrested revise their probability upward. Estimates suggest that beliefs about the probability of arrest significantly deter crime.