no code implementations • 7 May 2024 • Clément de Chaisemartin, Xavier D'Haultfœuille
If there are stayers with a period-two treatment equal to 0, the robust estimator is a difference-in-differences (DID) estimator using stayers as the control group.
no code implementations • 8 Feb 2024 • Clément de Chaisemartin, Xavier D'Haultfœuille, Gonzalo Vazquez-Bare
However, such estimators are not robust to heterogeneous treatment effects in general; they also rely on the linearity of treatment effects.
no code implementations • 9 Jun 2022 • Xavier D'Haultfœuille, Ao Wang, Philippe Février, Lionel Wilner
Despite the wide adoption of revenue management in many industries such as airline, railway, and hospitality, there is still scarce empirical evidence on the gains or losses of such strategies compared to uniform pricing or fully flexible strategies.
no code implementations • 13 May 2022 • Xavier D'Haultfœuille, Purevdorj Tuvaandorj
We develop a new permutation test for inference on a subvector of coefficients in linear models.
1 code implementation • 11 Apr 2022 • Xavier D'Haultfœuille, Christophe Gaillac, Arnaud Maurel
We study partially linear models when the outcome of interest and some of the covariates are observed in two different datasets that cannot be linked.
no code implementations • 8 Dec 2021 • Clément de Chaisemartin, Xavier D'Haultfœuille
Linear regressions with period and group fixed effects are widely used to estimate policies' effects: 26 of the 100 most cited papers published by the American Economic Review from 2015 to 2019 estimate such regressions.
no code implementations • 18 Dec 2020 • Clément de Chaisemartin, Xavier D'Haultfœuille
Under a parallel trends assumption, we show that the coefficient on each treatment identifies a weighted sum of that treatment's effect, with possibly negative weights, plus a weighted sum of the effects of the other treatments.