Using data from Mathematica's experimental evaluation of charter schools, this methodological study examines the validity of four different comparison group approaches to test whether these designs can replicate findings from a well-implemented random assignment study.

Randomized controlled trials (RCTs) are considered the gold standard in estimating treatment effects. When an RCT is infeasible, regression modeling or statistical matching are often used instead. Nonexperimental methods such as these could produce unbiased estimates if the underlying...

Using data from Mathematica's experimental evaluation of charter schools, this methodological study examines the validity of four different comparison group approaches to test whether these designs can replicate findings from a well-implemented random assignment study.