Chaisemartin, Clément de - In: Quantitative economics : QE ; journal of the … 8 (2017) 2, pp. 367-396
Instrumental variables (IVs) are commonly used to estimate the effects of some treatments. A valid IV should be as good as randomly assigned, it should not have a direct effect on the outcome, and it should not induce any unit to forgo treatment. This last condition, the so-called monotonicity...