Impacts of Norwegian Milk Quotas on Output Growth: A Modified Distance Function Approach
研究挪威奶牛场1976年以来的产出增长率，分解为产出、投入、社会经济和技术变化成分，发现牛奶配额显著抑制了产出增长，尤其是1983-1996年期间，且产出结构向肉类生产转移。
Abstract Quota regulations that prevent output expansion of farms and reallocation of output between farms can cause lower growth in output and productivity. The aim of this study was to explain the output growth rate of Norwegian dairy farms since 1976, and to decompose it into output, input, socioeconomic and technical change components. Instead of using the standard distance function approach for multi‐output technologies, we use a growth rate formulation, which automatically removes the farm‐specific effects. This formulation also helps to impose non‐negativity constraints on marginal products of inputs (input elasticities), which are often violated for many observations, especially when flexible functional forms are used. The farm‐level panel data cover three periods: before the quota scheme was introduced (1976–1982); the period with the most output‐restricting quota scheme (1983–1996); and the period with a more flexible quota scheme (from 1997 onwards). Results show that the milk quota regulations had a significant constraining effect on output growth, in particular on milk output in the period 1983–1996. Furthermore, the output mix has shifted towards meat production for the average farm. What emerges from this study is that output growth and technical change are negatively influenced by policy aims where productive performance has not been the primary objective, and that there is scope for increased farm growth if the quota regime is liberalised.