We randomly assign more than 6,000 students from 150 primary schools in Bangladesh to work on math assignments in one of three settings: individually, in groups with random schoolmates, or in groups with friends. The groups consist of four people and are balanced by average cognitive ability and...

We develop a theoretical model in which technology adoption decisions are based on the information received from others about the quality of a new technology and on their risk attitudes. We test the predictions of this model using a randomized field experiment in Bangladesh. We show that the...