Journal of Economic Literature · 2026 · Andrew Baker、Brantly Callaway、Scott Cunningham、Andrew Goodman-Bacon、Pedro H. C. Sant’Anna
中文摘要
双重差分（DiD）可以说是最流行的准实验研究设计。其规范形式——两组、两期——已被充分理解。然而，当研究者超出这一简单情形时，实证操作可能流于权宜。本文提供了一个组织框架，用以讨论不同类型的双重差分设计及其对应的双重差分估计量。文中讨论了协变量、权重、多时期处理以及交错（分批）处理。不过，该组织框架同样适用于双重差分方法的其他扩展。（JEL C23, H75, I12, I38）
Abstract
Difference-in-differences (DiD) is arguably the most popular quasi-experimental research design. Its canonical form, with two groups and two periods, is well understood. However, empirical practices can be ad hoc when researchers go beyond that simple case. This article provides an organizing framework for discussing different types of DiD designs and their associated DiD estimators. It discusses covariates, weights, handling multiple periods, and staggered treatments. The organizational framework, however, applies to other extensions of DiD methods as well. (JEL C23, H75, I12, I38)