The large literature on costly signaling and the somewhat scant literature on preference signaling had varying success in showing the effectiveness of signals. We use a field experiment to show that even when everyone can send a signal, signals are free and the only costs are opportunity costs,...

We examine the effect of single-sex schooling on students’ competitiveness by studying middle school students in Seoul who were randomly assigned to either single-sex or coeducational schools within their school districts. Contrary to popular belief and existing studies, our results suggest...

The large literature on costly signaling and the somewhat scant literature on preference signaling had varying success in showing the effectiveness of signals. We use a field experiment to show that even when everyone can send a signal, signals are free and the only costs are opportunity costs,...