This report, conducted by researchers at the Midwest Economic Policy Institute, the University of Wisconsin-Extension School for Workers, and the Project for Middle Class Renewal at the University of Illinois at Urbana-Champaign analyzes the course of unionization in Wisconsin, in the Milwaukee metropolitan statistical area (MSA), and in the United States from 2006 to 2015. The study of Iowa tracks unionization rates and investigates union membership across demographic, educational, sectoral, industry, and occupational classifications. The study subsequently evaluates the impact that labor union membership has on a worker’s hourly wage in Iowa and in the United States. Additionally, data on labor unions and similar labor organizations are included and analyzed. A few major findings of the report include: Declining union membership in Wisconsin has resulted from a number of factors, including the ongoing effects of Act 10 on the public sector and the continued loss of manufacturing jobs. From 2014 to 2015, union membership dropped 3.3 percentage points, from 11.6 percent to 8.3 percent.