This discussion paper updates and extends the analysis presented in iza dp 11136. Commissioned by policy institutions on the national and international level, iza provides comprehensive studies or shorter reports on current labor market policy issues. The author thanks three anonymous referees and the iza world of labor editors for many helpful suggestions on earlier drafts The author’s previous work contains a larger number of background references for the material presented here and has been used extensively in all major parts of this article [1], [2], [18], and [19]. Competing interests the iza world of labor project is committed to the iza code of conduct The author declares to have observed the principles outlined in the code
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