SUPPLY AND DEMAND FUNCTIONS FOR UK AGRICULTURE: BIASES OF TECHNICAL CHANGE AND THE RETURNS TO PUBLIC R&D
首次用英国农业数据（1954-1990）估计了公共研发的回报率，发现供给和需求弹性较低，但价格响应随时间增强，公共研发的边际回报率仅为18%，且对畜牧业影响最大。
This study is the first UK application of the integrated, single‐stage approach to estimating the returns to R&D. Fitting a residual profit function, which incorporates the technology variables, to new data for UK agriculture for 1954–1990 produces short‐ and long‐run estimates of the output supply and input‐demand price elasticities, elasticities of the effects of relaxing the non‐variable input constraints and shadow prices for these non‐variable factors. All of the supply and demand relationships are found to be inelastic, but the price‐responsiveness of the system has increased over time. The long‐run model, in which all of the inputs except land are treated as variable and private‐sector research is included, gives a marginal rate of return to public agricultural R&D of only 18 per cent. Estimates of the factor‐saving biases of the technology variables suggest that public R&D has had its greatest effect in the animal sector.