#  ResearchStats: Peng Ding 

 



####  calendar\_today Date and Time 

 **January 13, 2015** 

 12:00PM - 01:00PM EST 

####  pin\_drop Location 

 **Science Center Rm. 705**  



 

 



 

Title: Treatment Effect HeterogeneityAbstract: Applied researchers are increasingly interested in whether and how treatment effects vary in randomized evaluations, especially variation not explained by observed covariates. We propose a model-free approach for testing for the presence of such unexplained variation. To use this randomization-based approach, we must address the fact that the average treatment effect, generally the object of interest in randomized experiments, actually acts as a nuisance parameter in this setting. We explore potential solutions and advocate for a method that guarantees valid tests in finite samples despite this nuisance. We also show how this method readily extends to testing for heterogeneity beyond a given model, which can be useful for assessing the sufficiency of a given scientific theory. We finally apply our method to the National Head Start Impact Study, a large-scale randomized evaluation of a Federal preschool program, finding that there is indeed significant unexplained treatment effect variation.

 

 



 

 See also:- [ 2014 - 2015 ](/academic-year/2014-2015)
 
 

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