Wei, Quanling; Yan, Hong - In: Socio-Economic Planning Sciences 43 (2009) 1, pp. 40-54
Our earlier work [Wei QL, Yan H. Congestion and returns to scale in data envelopment analysis. European Journal of Operational Research 2004;153:641-60] discussed necessary and sufficient conditions for the existence of congestion together with aspects of returns to scale under an output-oriented...
