Firms are more productive on average in larger cities. Two explanations have been offered: agglomeration economies (larger cities promote interactions that increase productivity) and firm selection (larger cities toughen competition allowing only the most productive to survive). To distinguish...

We analyze delinquent networks of adolescents in the United States. We develop a dynamic network formation model showing who the key player is, i.e. the criminal who once removed generates the highest possible reduction in aggregate crime level. We then structurally estimate our model using data...

This paper studies whether conformism behavior affects individual outcomes in crime. We present a social network model of peer effects with ex-ante heterogeneous agents and show how conformism and deterrence affect criminal activities. We then bring the model to the data by using a very detailed...