Transforming Labor: A Comprehensive, Nationwide Comparison and Grading of Public Sector Labor Laws

Source: Priya Abraham, Commonwealth Foundation, Policy Report, November 13, 2016

From the summary:
In the last five years, Americans have seen an unprecedented sweep of public sector labor reforms across several states. Wisconsin, Michigan, Indiana—and most recently, West Virginia in July 2016—have all become right-to-work states. Other states have limited the scope of collective bargaining, increased the transparency of union contract negotiations, and created stronger protections for individual workers who do not want to be union members. For the first time since states enacted public sector collective bargaining laws in the mid-to-late twentieth century, right-to-work states outnumber forced-union states 26 to 24.