Being in the Right Place: A Natural Field Experiment on the Causes of Position Effects in Individual Choice

This paper uses a natural field experiment to better understand why individuals tend to select items at the top of lists. After randomizing the order in which new economics research papers are presented in email alerts and measuring the subsequent downloads, we provide robust evidence of position effects. Moreover, our novel user-level data offers two key findings: i) most users exhibit both top and bottom position effects, and ii) distinct groups of users consider the listed items in different orders. These results allow us to conclude that the causes of top position effects are complex and heterogeneous across individuals, but are most consistent with a version of choice fatigue where users consider the listed items in a non-monotonic order.