A Variable Is Exogenous If That Variable

Multiple Choice

A variable is exogenous if that variable:

A) has no effect on the treatment variable beyond the combined effects of other variables already in the determining function.
B) has no effect on the outcome variable beyond the combined effects of other variables already in the determining function.
C) has a strong correlation with the weather.
D) is uncorrelated with the residuals of a regression estimated by OLS.