Alternatives on a straightforward measure of allocative efficiency (typically a benefit-cost ratio or net social benefits expressed in monetary terms). Efficiency in this case is of course, defined by the Kaldor-Hicks compensation principle. Post-positivists lodge a raft of objections to cost benefit analysis, ranging from the heroic assumptions often necessary to make the technique mathematically tractable to perceived affront to democratic values inherent in its intellectual framework. For example because CBA requires all costs and benefits to be monetized, it requires putting dollar values on things that strike many as beyond the ability of markets even theoretical benchmark markets to price. Clean air human life and freedom from sickness or disease for example have all been monetized by CBA studies (Boardman et al. 2001, 1-3). Such valuations are frequently challenged as either inaccurate, misleading or meaningless (Wolff and Haubrich 2006).