Address for correspondence:

Running head: Information acquisition and choice under uncertainty This paper presents a model where individuals have imperfect information and there is an opportunity cost of learning. It shows that the endogenous decision to collect costly information before taking an action has a systematic effect on choices. More precisely, consider two alternatives with ex ante identical expected payoff but different variances. The model predicts that, after the learning process is stopped, a majority of individuals will select the alternative with largest payoff-variance. The result persists when agents have multiple sources of information. Applications to entrepreneurial investments, composition of advisory committees, and judicial decision-making are discussed.