Data and Code for: From Mad Men to Maths Men: Concentration and Buyer Power in Online Advertising

This project contains the data and replication file for: "From Mad Men to Maths Men: Concentration and Buyer Power in Online Advertising" <br>Abstract: This paper analyzes the impact of intermediary concentration on the allocation of revenue in online platforms. We study {sponsored search} documenting how advertisers increasingly bid through a handful of specialized intermediaries. This enhances automated bidding and data pooling, but lessens competition whenever the intermediary represents competing advertisers. Using data on nearly 40 million Google keyword-auctions, we first apply machine learning algorithms to cluster keywords into thematic groups serving as relevant markets. Using an instrumental variable strategy, we estimate a decline in the platform's revenue of approximately 11 percent due to the average rise in concentration associated with intermediary M&amp;A activity.<br><br><br><br>