Diff-in-Diff in Panel Data

Overview

This module covers regression approaches to difference-in-differences estimation (without staggered treatment timing). We review the basic two-by-two difference-in-differences regression specifications, and discuss extensions that allow for continuous variation in treatent intensity and the inclusion of period-specific and unit-specific fixed effects.

Readings

Does a ban on informal health providers save lives? Evidence from Malawi by Susan Godlonton and Edward Okeke.

Lecture Slides

A handout version of the lecture slides is available here.

Video Lectures from 2021

Lecture 5.1: 2X2 Difference-in-Differences Specifications (19:34)

Lecture 5.2: Diff-in-Diff with Continuous Treatment Variation (28:06)

Lecture 5.3: Diff-in-Diff with Time Period Fixed Effects (19:14)

Empirical Exercise

The in-class activity as a do file or pdf.

The empirical exercise as a do file or pdf.

A web version of the empirical exercise is available here.

Acknowledgments

Special thanks to Patrick Blanchenay, Garret Christensen, Liz Cascio, Jess Goldberg, Guy Grossman, Kirabo Jackson, Michael Kevane, Scott Imberman, Manisha Shah, and Mike Urbancic for their diff-in-diff suggestions.