Laffers, Lukas; Mellace, Giovanni - Institut for Virksomhedsledelse og Økonomi, Syddansk … - 2015
In this paper we show that the testable implications derived in Huber and Mellace (2013) are the best possible to detect invalid instruments, in the presence of heterogeneous treatment effects and endogeneity. We also provide a formal proof of the fact that those testable implications are only...