We measure the effectiveness of competitive advertising on brand search using alarge-scale, quasi-experimental ad allocation on Bing. Competitors are able to stealtraffic from the focal brand, and they steal an order of magnitude more clicks if the focalbrand's link is exogenously removed from...

Standard search models assume that consumers actively decide on the order, identity, and number of products they search. We document that online, a large fraction of searches happen in a more passive manner, with consumers merely reacting to online advertisements that do not allow them to choose...

Online advertising offers unprecedented opportunities for measurement. A host of new metrics, clicks being the leading example, have become widespread in advertising science. New data and experimentation platforms open the door for firms and researchers to measure true causal effects of...