Yahoo! Research partnered with a nationwide retailer to study the effects of online display advertising on both online and in-store purchases. We use a randomized field experiment on 3 million Yahoo! users who are also past customers of the retailer. We find statistically significant evidence...

Field experiments occupy a middle ground between laboratory experiments and naturally occurring field data. The idea is to perform a controlled experiment that captures important characteristics of the real world. Relative to traditional empirical economics, field experiments provide an...