Jacques: Surely you don't mean to suggest that reform priorities should be based on the average cost composition of production? (I don't pay much ady-to-day for water, but I very much depend on a reliable supply.) Shouldn't we be comparing and looking for excessive costs that can be addressed through policy reforms or other public interventions, as well as those factors that may be associated with lower productivity than relevant comparators? With regard to electricity, the 2009 ICA was quite clear that the timing of the survey influenced the high perceptual priority placed on that factor: "The timing of the survey probably contributed to the firm managers‘ extremely high concern about power supply. Although the poor performance of the power sector has been a problem in Tanzania for many years, the Enterprise Survey took place during a serious power crisis that hit the country in 2006. Growing demand and a steep drop in hydroelectric generation capacity led to load shedding (i.e., rolling, intentional power outages) and almost daily outages for many firms throughout the country." [Tanzania ICA 2009]. The perceptions point to a problem, but the explanation of that perception may or may not lead to public interventions depending on supplementary analysis. Survey findings by themselves are not enough to go on, but can provide some useful quantitative as well as perceptual indicators on multiple issues, as can other indicators. The important thing is not to reify the data on constraint rankings, but to use each data source intelligently and to draw from multiple sources.