Mere observation of others' choices can be informative about product quality. This paper develops an individual-level dynamic model of observational learning and applies it to a novel data set from the U.S. kidney market, where transplant candidates on a waiting list sequentially decide whether...

Popularity information is usually thought to reinforce existing sales trends by encouraging customers to flock to mainstream products with broad appeal. We suggest a countervailing market force: popularity information may benefit niche products with narrow appeal disproportionately, because the...

Microloan markets allow individual borrowers to raise funding from multiple individual lenders. We use a unique panel data set that tracks the funding dynamics of borrower listings on Prosper.com, the largest microloan market in the United States. We find evidence of rational herding among...