@TECHREPORT {SFB649DP2017-018,
  AUTHOR={Almosova, Anna and Burda, Michael C. and Voigts, Simon},
  TITLE={{Social Security Contributions and the Business Cycle}},
  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/SFB649DP2017-018.pdf},
  NUMBER={2017-018}
}