Knowledge that Transforms

We study the effects of network externalities within a protocol for matching faculty to offices in a new building. Using web and survey data on faculty's attributes and choices, we identify the different layers of the social network: institutional affiliation, coauthorships, and friendships. We quantify the effects of network externalities on choices and outcomes, disentangle the layers of the networks, and quantify their relative influence. Finally, we assess the protocol used from a welfare perspective. Our study suggests the importance and feasibility of accounting for network externalities in assignment problems and evaluates techniques that can be employed to this end.

This paper provides new evidence on the time use and emotional well-being of unemployed individuals in the weeks before and after starting a new job. The major findings are: (1) time spent on home production drops sharply at the time of re-employment, even when controlling for individual fixed effects; (2) time spent on leisure-related activities, which the unemployed find less enjoyable, drops on re-employment, but less so when controlling for individual fixed effects; (3) the unemployed report higher levels of sadness during specific episodes of the day than the employed; and (4) sadness decreases abruptly at the time of re-employment.

After Lehman Brothers filed for bankruptcy in September 2008, cross-border bank lending contracted sharply. To explain the severity and variation in this contraction, we analyze detailed data on cross-border syndicated lending by 75 banks to 59 countries. We find that banks which had to write down sub-prime assets, refinance large amounts of long-term debt, and which experienced sharp declines in their market-to-book ratio, transmitted these shocks across borders by curtailing their lending abroad. While shocked banks differentiated between countries in much the same way as less constrained banks, they restricted their lending more to small borrowers.

We advance quantitative-theoretic models of sovereign debt by proving the existence of a downward sloping equilibrium price function for long-term debt and implementing a novel method to accurately compute it. We show that incorporating long-term debt allows the model to match Argentina's average external debt-to-output ratio, average spread on external debt, the standard deviation of spreads, and simultaneously improve upon the model's ability to account for Argentina's other cyclical facts. We also investigated the welfare properties of maturity length and showed that if the possibility of self-fulfilling rollover crises is taken into account, long-term debt is superior to short-term debt.

It is often suggested that currency unions unduly inhibit the efficient adjustment of real exchange rates. Recently, this has been seen as a key failure of the Eurozone. This paper presents evidence that throws doubt on this conclusion. Our evidence suggests that real exchange rate movement within the Eurozone was at least as compatible with efficient adjustment as the behavior of real exchange rates for the floating rate countries outside the Eurozone. This interpretation is consistent with a model in which nominal exchange rate movements give rise to persistent deviations from the law of one price in traded goods.

Cross-border production chains tend to include geographically proximate countries. This suggests that increases in fragmentation should be largest among nearby trading partners, and thus may serve to localize gross trade. Using data on gross and value added trade from 1970-2009, we present three results supporting this conjecture. First, value added to export ratios are lower and falling more rapidly within geographic regions than between them. Second, gross trade travels shorter distances from source to destination than value added trade, and this gap is growing over time. Third, bilateral value added to export ratios have fallen most among nearby trading partners.

Existing studies show that individuals who retire replace some private consumption with home production, but do not consider joint behavior of couples. Here we analyze the causal effect of retirement of each partner on hours of home production for both partners in a couple. Our identification strategy exploits the earliest age retirement laws in France, enabling a fuzzy regression discontinuity approach. We find that own retirement significantly increases own hours of home production and the effect is larger for men than for women. Moreover, retirement of the female partner significantly reduces male hours of home production but not vice versa.

This study empirically examines whether Wikipedia has a neutral point of view. It develops a method for measuring the slant of 28 thousand articles about US politics. In its earliest years, Wikipedia's political entries lean Democrat on average. The slant diminishes during Wikipedia's decade of experience. This change does not arise primarily from revision of existing articles. Most articles arrive with a slant, and most articles change only mildly from their initial slant. The overall slant changes due to the entry of articles with opposite slants, leading toward neutrality for many topics, not necessarily within specific articles.

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.

When a city experiences a decline in income or population, do all neighborhoods within the city decline equally? Or, do some neighborhoods decline more than others? What are the characteristics of the neighborhoods that decline the most? We answer these questions by looking at what happened to neighborhoods within Detroit as Detroit experienced a sharp decline in income and population from the 1980s to the late 2000s. We find patterns of changes in income and population that are consistent with the model and empirical patterns of gentrification presented in Guerrieri, Hartley, and Hurst (2011), only playing out in reverse.