Timothy G. Conley
Department of Economics
Social Science Centre, Room 4071
London, Ontario, Canada, N6A 5C2
Information about this author at RePEc
NBER Working Papers and Publications
|July 2015||Social Interactions, Mechanisms, and Equilibrium: Evidence from a Model of Study Time and Academic Achievement|
with Nirav Mehta, Ralph Stinebrickner, Todd Stinebrickner: w21418
We develop and estimate an equilibrium model of study time choices of students on a social network. We examine how network structure interacts with student characteristics to affect academic achievement. Due to data limitations, few papers examine the mechanisms through which peer effects operate. The model is designed to exploit unique data collected in the Berea Panel Study. Study time data allow us to quantify an intuitive mechanism for social interactions: the cost of own study time may depend on friend study time. Social network data allow study time choices and resulting academic achievement to be embedded in an equilibrium framework. We find friend study time strongly affects own study time, and, therefore, student achievement. Not taking into account equilibrium behavior would dras...
|July 2005||Inference with "Difference in Differences" with a Small Number of Policy Changes|
with Christopher Taber: t0312
Difference in differences methods have become very popular in applied work. This paper provides a new method for inference in these models when there are a small number of policy changes. This situation occurs in many implementations of these estimators. Identification of the key parameter typically arises when a group "changes" some particular policy. The asymptotic approximations that are typically employed assume that the number of cross sectional groups, N, times the number of time periods, T, is large. However, even when N or T is large, the number of actual policy changes observed in the data is often very small. In this case, we argue that point estimators of treatment effects should not be thought of as being consistent and that the standard methods that researchers use to perform ...