Topic summary
Difference-in-differences

Extracted from the Wikipedia article Difference in differences.
In economic history
Difference-in-differences has also been applied to the study of historical events, particularly in the field of economic history, where researchers rely on natural experiments to investigate long-run outcomes. By comparing regions or groups that were differentially exposed to shocks such as disease, institutional change, or wartime destruction, scholars have used the method to identify causal effects that cannot be observed directly.