This paper studies how imposing norms on contribution behavior affects individuals' intrinsic motivation. We consider the church levy, which the Catholic Church in Germany collects as a charitable donation, despite the fact that the levy is legally a tax. We design a randomized field experiment...

Crowded trades by similarly trading peers influence the dynamics of asset prices, possibly creating systemic risk. We propose a market clustering measure using granular trading data. For each stock the clustering measure captures the degree of trading overlap among any two investors in that...