Individual outcomes are highly correlated with group average outcomes, a fact often interpreted as a causal peer effect. Without covariates, however, outcome-on-outcome peer effects are vacuous, either unity or, if the average is defined as leave-out, determined by a generic intraclass...

Little is known about the economic mechanisms leading to the high level of clustering in behavior commonly observed in the data. We present a model where agents can interact according to three distinct mechanisms, and we derive testable implications which allow us to distinguish between the...

This paper estimates the long-term effects of the global recession of 2008-2009 on output in 23 countries. I measure these effects by comparing current estimates of potential output from the OECD and IMF to the path that potential was following in 2007, according to estimates at the time. The...

This paper uses a database covering the universe of French firms for the period 1990--2007 to provide a forensic account of the role of individual firms in generating aggregate fluctuations. We set up a simple multi-sector model of heterogeneous firms selling to multiple markets to motivate a...

We make use of a new data resource, merged birth and school records for all children born in Florida from 1992 to 2002, to study the effects of birth weight on cognitive development from kindergarten through schooling. Using twin fixed effects models, we find that the effects of birth weight on...

We decompose the squared VIX index, derived from US S&P500 options prices, into the conditional variance of stock returns and the equity variance premium. The latter is increasing in risk aversion in a wide variety of economic settings. We tackle several measurement issues assessing a plethora...

We present new data documenting medieval Europe's "Commercial Revolution'' using information on the establishment of markets in Germany. We use these data to test whether medieval universities played a causal role in expanding economic activity, examining the foundation of Germany's first...

We survey the economic literature, both theoretical and empirical, on the choice of intellectual property protection by firms. Our focus is on the tradeoffs between using patents and disclosing versus the use of secrecy, although we also look briefly at the use of other means of formal...

The American Recovery and Reinvestment Act of 2009 (ARRA) targeted substantial School Improvement Grants (SIGs) to the nation's "persistently lowest achieving" public schools (i.e., up to $2 million per school annually over 3 years) but required schools accepting these awards to implement a...

We show that the welfare of a country's infinitely-lived representative consumer is summarized, to a first order, by total factor productivity (TFP) and by the capital stock per capita. These variables suffice to calculate welfare changes within a country, as well as welfare differences across...