Revision requested by The American Economic Review
Abstract: We show that the stock market may fail to aggregate information even if it appears to be efficient; the resulting collapse in the dissemination of information may drastically reduce welfare. We solve a macroeconomic model in which information about fundamentals is dispersed and households make small, correlated errors around their optimal investment policies. As information aggregates in the market, these errors amplify and crowd out the information content of stock prices. When stock prices reflect less information, the perceived and the actual volatility of stock returns rise. This increase in financial risk makes holding stocks unattractive, distorts the long-run level of capital accumulation, and causes costly (first-order) distortions in the long-run level of consumption.
(with Rui Mano)
Abstract: We decompose the covariance of currency returns with forward premia into a cross-currency, a between-time-and-currency, and a cross-time component. The surprising result of our decomposition is that the cross-currency and cross-time-components account for almost all systematic variation in expected currency returns, while the between-time-and-currency component is statistically and economically insignificant. This finding has three surprising implications for models of currency risk premia. First, it shows that the two most famous anomalies in international currency markets, the carry trade and the Forward Premium Puzzle (FPP), are separate phenomena that may require separate explanations. The carry trade is driven by persistent differences in currency risk premia across countries, while the FPP appears to be driven primarily by time-series variation in all currency risk premia against the US dollar. Second, it shows that both the carry trade and the FPP are puzzles about asymmetries in the risk characteristics of countries. The carry trade results from persistent differences in the risk characteristics of individual countries; the FPP is best explained by time variation in the average return of all currencies against the US dollar. As a result, existing models in which two symmetric countries interact in financial markets cannot explain either of the two anomalies.
Published and Forthcoming Papers
The Journal of Finance (2013) 68(6), forthcoming
Winner of the Austrian Central Bank's 2009 Klaus Liebscher Award for best paper on European Monetary Union and Integration Issues
Winner of the Leo Melamed Prize for Outstanding Research in Finance
Abstract: Differences in real interest rates across developed economies are puzzlingly large and persistent. I propose a simple explanation: Bonds issued in the currencies of larger economies are expensive because they insure against shocks that affect a larger fraction of the world economy. I show that differences in the size of economies indeed explain a large fraction of the cross-sectional variation in currency returns. The data also support a number of additional implications of the model: The introduction of a currency union lowers interest rates in participating countries and stocks in the non-traded sector of larger economies pay lower expected returns.
(with Daron Acemoglu and James A. Robinson)
The Quarterly Journal of Economics (2011) 126(2), 895-946.
Abstract: We document a statistical association between the severity of the mass murder of Jews (the Holocaust) by the Nazis during World War II and long-run economic and political outcomes within Russia. Cities that experienced the Holocaust most intensely have grown less and administrative districts (oblasts) where the Holocaust had the largest impact have lower urban populations, GDP per capita and lower average wages today. In addition these same cities and oblasts exhibit a higher vote share for Communist candidates since the collapse of the Soviet Union. Although we cannot rule out the possibility that these statistical relationships are caused by other factors, the overall patterns appear generally robust. We provide evidence on one possible mechanism that we hypothesize may link the Holocaust to the present---the change it induced in the social structure, in particular the size of the middle class, across different regions of Russia. Before World War II, Russian Jews were predominantly in white collar (middle class) occupations and the Holocaust appears to have had a direct negative effect on the size of the middle class after the war.
The American Economic Review (2011) 101(2), Papers and Proceedings, 402-405.
Abstract: We present a model with dispersed information in which investors decide whether or to what degree they want to allow their behavior to be influenced by "market sentiment". Investors who choose to insulate their decision from market sentiment earn higher expected returns, but incur a small mental cost. We show that if information is moderately dispersed across investors, even a very small mental cost (on the order of 0.001% of consumption) may generate a significant amount of sentiment in equilibrium: Individuals who choose to be swayed by sentiment increase uncertainty about the future and make it less costly for others to be swayed by sentiment as well. Market sentiment thus emerges as a tragedy of the commons.
The Quarterly Journal of Economics (2013) 128(3), 1219-1271
Abstract: We use the fall of the Berlin Wall in 1989 to show that personal relationships which individuals maintain for non-economic reasons can be an important determinant of regional economic growth. We show that West German households who have social ties to East Germany in 1989 experience a persistent rise in their personal incomes after the fall of the Berlin Wall. Moreover, the presence of these households significantly affects economic performance at the regional level: it increases the returns to entrepreneurial activity, the share of households who become entrepreneurs, and the likelihood that firms based within a given West German region invest in East Germany. As a result, West German regions which (for idiosyncratic reasons) have a high concentration of households with social ties to the East exhibit substantially higher growth in income per capita in the early 1990s. A one standard deviation rise in the share of households with social ties to East Germany in 1989 is associated with a 4.6 percentage point rise in income per capita over six years. We interpret our findings as evidence of a causal link between social ties and regional economic development.
Work in Progress
The Social Value of Private Information
(with Thomas M. Mertens)
(with Thomas M. Mertens)
Patronage Networks and the Balance of Power in Egypt's Arab Spring
(with Daron Acemoglu and Ahmed Tahoun)
Ethnic Minorities and International Trade
(with Konrad B. Burchardi and Thomas Chaney)
Heterogeneous Information in DSGE Models
(with Thomas M. Mertens)