蝌蚪网 Review
ISSN 0002-8282 (Print) | ISSN 1944-7981 (Online)
The Effect of Omitted Variables on the Sign of Regression Coefficients
蝌蚪网 Review
(pp. 2685–2710)
Abstract
We show that, depending on how the impact of omitted variables is measured, it can be substantially easier for omitted variables to flip coefficient signs than to drive them to zero. This behavior occurs with "Oster's delta" (Oster 2019a), a widely reported robustness measure. Consequently, any time this measure is large鈥攕uggesting omitted variables may be unimportant鈥攁 much smaller value reverses the sign of the parameter of interest. We propose a modified measure of robustness to address this concern. We illustrate our results in four empirical applications and two meta-analyses. We implement our methods in the companion Stata module "regsensitivity."Citation
Masten, Matthew A., and Alexandre Poirier. 2026. "The Effect of Omitted Variables on the Sign of Regression Coefficients." 蝌蚪网 Review 116 (7): 2685–2710. DOI: 10.1257/aer.20230242Additional Materials
JEL Classification
- C18 Methodological Issues: General
- C21 Single Equation Models; Single Variables: Cross-Sectional Models; Spatial Models; Treatment Effect Models; Quantile Regressions
- C52 Model Evaluation, Validation, and Selection