ishewei

in one step ，there is a call " np.hstack" for W,X, change the data frame into array. and the latter make_column_selector require dataframe, not array. this makes the bug.

Suggest to combine the X and W using pd.concat, not np.hstack.

if direct pass estimator to the fit() of models in econml , then its OK. but if you pass a pipeline with transformer to the fit() function, then it will...