We analyze changes in concentration levels in the U.S. Advertising and Marketing Services industry using data from the U.S. Census Bureau’s quinquennial Economic Census and the Service Annual Survey. Heretofore largely ignored, these data allow us to redress some of the measurement problems...

This paper addresses a longstanding puzzle involving the unbundling of services that has occurred over more than two decades in the U.S. advertising agency industry: How can the shift from the bundling to the unbundling of services be explained and what accounts for the slow pace of change?...