Productivity of New York Dairy Farms Measured by Nonparametric Malmquist Indices
利用非参数规划方法估计产出距离函数，分解1985至1993年70个纽约奶牛场的生产率变化为技术效率和技术进步，发现年均增长2.6%主要来自技术进步，但平均效率略有下降。
The productivity of 70 individual New York dairy farms, decomposed into technical efficiency change and technological change components, was measured annually from 1985 to 1993 from output distance functions estimated using nonparametric programming methods. Technology is measured regressively only if it is regressive to all previous periods rather than just the immediate previous period. Productivity increase averaged 2.6 per cent annually, mostly from gains in technological improvements, since average efficiency decreased slightly. Twenty‐five per cent of the farms failed to increase productivity sufficiently over the period to offset the decreased ratio of output to input prices.