The discussion about the bias due to input (or output) aggregation in efficiency measurement based on data envelopment analysis, recently revisited by Tauer (2001) and Fare and Zelenyuk (2002) is continued. Attention is focused on the direction and the bounds of the aggregation bias.

We discuss how to measure allocative efficiency without presuming technical efficiency. This is relevant when it is easier to introduce reallocations than improvements of technical efficiency. We compare the approach to the traditional one of assuming technical efficiency before measuring...

This paper critiques a recent attempt to model pollution prevention using data envelopment analysis (DEA). We contribute an alternative model which explicitly models joint provision of desirable and undesirable outputs (a la Shephard and Fare (1974)), using weak disposability of output. We also...