Tracking Growth in Unionized Charter Schools

As more charter schools consider unionizing, policymakers and advocates need clear facts rather than anecdotes. Basis examined national and state-level data to track how many charter schools are unionized, where unionization is growing, and how patterns have changed over time. Their work highlighted that while only about one in nine charter schools nationwide had unions in the mid-2010s, unionization was rising rapidly in certain places – especially Illinois and major cities like Chicago – often driven by deliberate organizing campaigns.

By turning scattered data into a clear picture of trends, the project helped education leaders understand where unionization is expanding, how much of it is required by state law versus chosen voluntarily by teachers, and what this means for the future of the charter sector. These findings can inform future research on how unionization relates to school quality and teacher working conditions and help authorizers, policymakers, and advocacy groups respond thoughtfully as more charter teachers weigh whether to organize.