Vincent, CharlesFäre, RolfGrosskopf, Shawna2019-09-032019-09-032015https://repositorio.pucp.edu.pe/index/handle/123456789/166786This short communication complements the DEA model proposed by Lovell and Pastor (Eur. J. Oper. Res. 118 (1999), 46-51), by incorporating both positive and negative criteria in the model. As such, we propose a DEA model, known as pure DEA, using a directional distance function approach.enginfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/pe/Data envelopment analysisInvarianceDirectional distance functioninfo:eu-repo/semantics/workingPaperhttp://purl.org/pe-repo/ocde/ford#5.02.04http://dx.doi.org/10.7835/ccwp-2015-09-0016