@TECHREPORT {SFB649DP2017-007,
  AUTHOR={Breunig, Christoph},
  TITLE={{Testing Missing at Random using Instrumental Variables}},
  YEAR=2017,
  INSTITUTION={Sonderforschungsbereich 649, Humboldt Universit\"{a}t zu Berlin, Germany},
  TYPE={SFB 649 Discussion Paper},
  NOTE={available at http://sfb649.wiwi.hu-berlin.de/papers/pdf/SFB649DP2017-007.pdf},
  NUMBER={2017-007}
}