Before revision:  An empirical application to the impact of micro-credit on economic development illustrates the use of the approach in randomized experiments . An additional application to the impact of the gender discrimination on wages illustrates the potential use of the approach in observational studies, where machine learning methods can be used to condition flexibly on very high-dimensional controls .
After revision:  An empirical application to the impact of micro-credit on economic development illustrates the use of the approach with two randomized experiments in development on the effects of microcredit and nudges to stimulate immunization demand .