油田生产函数的进一步研究

采用全微分处理的方法，对以往在Cobb-Douglas生产函数中加入自然减产率和成本增加率的方法进行了理论分析，指出该方法隐含资源禀赋的变化对产出的影响是通过技术进步的减弱而实现的不合理假设。根据油田典型生产结构，提出了一种以资源、资本和人力为三要素的超越对数式时变生产函数，利用我国15家油田1995-2003年的相关数据进行了实证研究，通过对比分析证明了所提模型的有效性，估计结果认为资源投入的重要性体现在平方项上，其系数为正，说明资源投入对油田的产出影响是递增的。研究表明，所提生产函数设定方式能够更好地体现油田生产特点，能正确反映资源条件变化对油田生产的影响，能深刻揭示技术进步对油田产出的影响。

FURTHER RESEARCH ON OILFIELD PRODUCTION FUNCTION

By means of total differential analysis method, it is pointed out the formerly proposed method of modifying Cobb-Douglas production function by adding natural productivity decreasing rate and cost increasing rate has an unrealistic supposition, that is, it implies that resource stock of oilfield impacts output through weakening of technology progress. According to typical production structure of oilfield, the authors of the paper propose a timevarying translog stochastic frontier production function of oilfields with three inputs of resource stock, capital, and labor. The function is applied empirically by using the data collected from 15 oilfields in China with time span of 1995—2003. Estimation results show that the coefficient of square term of resource stock input is significantly positive, which means resource stock input has an increasing impact on the oilfields output. By comparison, the efficacy of the tranlog function specification can be confirmed; it can capture the characteristics of an oilfield production better with two prominent features, that is, reflecting impacts of resource stock correctly and revealing impacts of technology progress profoundly.