This note adds to the discussion originating from Card and Krueger (Am Econ Rev 84:772–793, <CitationRef CitationID="CR2">1994</CitationRef>) and Neumark and Wascher (Am Econ Rev 90:1362–1396, <CitationRef CitationID="CR3">2000</CitationRef>) by re-evaluating their results using the semiparametric difference-in-differences estimator introduced in Abadie (Rev Econ Stud...</citationref></citationref>