treatment. This last condition, the so-called monotonicity condition, is often implausible. This paper starts by showing that … actually, IVs are still valid under a weaker condition than monotonicity. It then derives conditions that are sufficient for … applications where this weaker condition is applicable while monotonicity is not. Overall, this paper extends the applicability of …

treatment. This last condition, the so-called monotonicity condition, is often implausible. This paper starts by showing that … actually, IVs are still valid under a weaker condition than monotonicity. It then derives conditions that are sufficient for … applications where this weaker condition is applicable while monotonicity is not. Overall, this paper extends the applicability of …

"less defiers than compliers" condition is substantially weaker than monotonicity. It has two implications which are …Monotonicity is not necessary for the Wald ratio to identify a Local Average Treatment Effect. Under random assignment … and exclusion restriction, if for every value of potential outcomes there are more compliers than defiers, the Wald ratio …

We show that the Wald statistic still identifies a causal effect if instrument monotonicity is replaced by a weaker …

The instrumental variable method relies on strong "no-defiers" condition, which requires that the instrument affect … every subject's treatment decision in the same direction. This paper shows that "no-defiers" can be replaced by a weaker … "compliers-defiers" condition, which requires that a subgroup of compliers have the same size and the same distribution of …