Abstract
Publishers' statements are often the only timely circulation data available to media planners and buyers. Many advertising purchasers depend on individual magazines guaranteed circulation (often called a rate base) to ensure that their advertisement purchase hits certain minimal levels of audience delivery. This study examines these issues in two time periods: 2001-2002 and 2003-2005. Unfortunately, we find that 25% to 30% of individual magazine issues fail to achieve their guaranteed audience. Even more surprising, audit reports find significantly larger numbers of issues miss their rate base compared to what is claimed in publishers' reports. The first data set found that 75 percent of issues exceed the rate base and that magazines are more likely to exceed their rate base by a large margin than they are to fall short of their rate base by a large margin. However, the amount of "bonus circulation" over the rate base fell in the second time period with fewer issues falling short of their rate base by large amounts and more issues missing their rate base by a large amount. Across almost all measures, the problem of missing rate bases and discrepancies between publishers' statements and audit reports got significantly worse during 2003-2005.