Charter schools have been growing in the United States and worldwide over the past two decades, and there is considerable interest in how they affect students remaining in traditional public schools (TPSs). Charter schools present important policy questions, as they often compete for the same students, educators, and resources as TPSs. This brief explores how charter schools affect outcomes of TPS students using a detailed data set from 12 large and diverse districts in Florida that includes standardized math scores for each student between 2001 and 2014, standardized reading scores between 2001 and 2017, attendance data from the 2002-03 to 2009-10 school years, and demographic data on each student. [This research brief is based on David N. Figlio, Cassandra Hart, and Krzysztof Karbownik, "Competitive Effects of Charter Schools," National Bureau of Economic Research Working Paper no. 32120, February 2024.]