The total gross annual research benefits (GARB) depend primarily on the size of the (time varying) research-induced supply shift (expressed as a vertical shift by an amount equal to a proportion, of the initial price) and the scale of the industry to which it applies.1 Indeed, a common approximation introduced by Griliches (1958) is GARB = kPQ, where P is the commodity price and Q is the annual quantity to which the supply shift applies. This aspect is often governed by the general nature of the analysis (e.g. evaluation of the benefits from the development of a particular varietal improvement compared with evaluation of a national agricultural research system, whether conducted ex ante or ex post) as well as the availability of data and other information. The nature of the research-induced supply shift has been controversial because it matters, especially for findings concerning the distribution of benefits, and is not easy to observe.