Was the Depression forecastable? After the crash, how long should it have taken contempo rary forecasters to realize how severe the downturn was going to be? These questions are addressed by studying the predictions of the Harv ard Economic Service and Yale's Irving Fisher during 1929 and the ear ly 1930s. The data assembled by the Harvard and Yale forecasters, tog ether with modern historical data, are subjected to statistical analy sis to learn whether their verbal pronouncements were consistent with the data. Both the Harvard and Yale forecasters were systematically too optimistic. Yet, nothing in the data suggests that the optimism w as unwarranted.

We explain a counterintuitive empirical finding: Firms facing more import competition do more innovation. In our model, factors are trapped inside a firm. An increase in import competition encourages a firm to innovate by reducing the opportunity cost of inputs. Without trapped factors, trade liberalization leads to a small permanent increase in the worldwide rate of growth. With trapped factors, firms that face more import competition do relatively more innovation. The extra innovation induced by trapped factors induces a small permanent increase in aggregate output, consumption, and welfare, generalizing the appropriate estimate of the gains from trade.

Inputs and Impacts in Charter Schools: KIPP Lynn by Joshua D. Angrist, Susan M. Dynarski, Thomas J. Kane, Parag A. Pathak and Christopher R. Walters. Published in volume 100, issue 2, pages 239-43 of American Economic Review, May 2010

Risk Aversion and Incentive Effects: Comment by Glenn W. Harrison, Eric Johnson, Melayne M. McInnes and E. Elisabet Rutström. Published in volume 95, issue 3, pages 897-901 of American Economic Review, June 2005

Distributional and Efficiency Impacts of Gasoline Taxes: An Econometrically Based Multi-market Study by Antonio M. Bento, Lawrence H. Goulder, Emeric Henry, Mark R. Jacobsen and Roger H. von Haefen. Published in volume 95, issue 2, pages 282-287 of American Economic Review, May 2005

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

Mixing across racial and ethnic lines could spur understanding or inflame tensions between groups. We find that white students at a large state university randomly assigned African American roommates in their first year were more likely to endorse affirmative action and view a diverse student body as essential for a high-quality education. They were also more likely to say they have more personal contact with, and interact more comfortably with, members of minority groups. Although sample sizes are too small to provide definitive evidence, these results suggest students become more empathetic with the social groups to which their roommates belong.

We study the design of mechanisms satisfying a novel desideratum: privacy. This requires the mechanism not reveal 'much' about any agent's type to other agents. We propose the notion of joint differential privacy: a variant of differential privacy used in the privacy literature. We show by construction that mechanisms satisfying our desiderata exist when there are a large number of players, and any player's action affects any other's payoff by at most a small amount. Our results imply that in large economies, privacy concerns of agents can be accommodated at no additional 'cost' to standard incentive concerns.

Systemic risk must include the housing market, though economists have not generally focused on it. We begin construction of an agent-based model of the housing market with individual data from Washington, DC. Twenty years of success with agent-based models of mortgage prepayments give us hope that such a model could be useful. Preliminary analysis suggests that the housing boom and bust of 1997-2007 was due in large part to changes in leverage rather than interest rates.