Empirical Economics

, Volume 53, Issue 3, pp 1281–1286 | Cite as

A note on testing instrument validity for the identification of LATE

  • Lukas LaffersEmail author
  • Giovanni Mellace


In this paper, we show that the testable implications derived in Huber and Mellace (Rev Econ Stat 97:398, 2015) are the best possible to detect invalid instruments in the presence of heterogeneous treatment effects and endogeneity. We also provide formal proof of the fact that those testable implications are only necessary, but not sufficient, conditions for instrument validity.


Testing IV validity Local average treatment effect Moment inequalities Bounds 

JEL Classification

PC1 C4 C12 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.Department of Mathematics, Faculty of Natural SciencesMatej Bel UniversityBanska BystricaSlovakia
  2. 2.Department of Business and EconomicsUniversity of Southern DenmarkOdenseDenmark

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