@article{CaliendoMahlstedtMitnik2017,
  author    = {Marco Caliendo and Robert Mahlstedt and Oscar A. Mitnik},
  title     = {Unobservable, but unimportant? The relevance of usually unobserved variables for the evaluation of labor market policies},
  journal   = {Labour economics : an international journal},
  volume    = {46},
  pages     = {14 -- 25},
  doi       = {10.1016/j.labeco.2017.02.001},
  year      = {2017},
}