A METHOD FOR ESTIMATING THE DEMAND FOR AGRICULTURAL MACHINERY IN THE UK
利用英国农业设备销售数据的特点，提出一种估算可变折旧率的方法，从而更准确地估计投资需求函数，对研究农业资本形成和投资决策的学者有参考价值。
In this paper an investment demand function is estimated, making use of some particular characteristics of data on the sales of agricultural equipment in the UK. The characteristics are that, first, much of agricultural equipment is deliverable quickly from stock and does not appear to be supply‐constrained, thus allowing equality of actual and desired capital stocks as a working hypothesis. Second, frequent replacement of machinery leads to depreciation rates which are high and variable. A method is presented to calculate a variable depreciation rate for each period and the resulting estimates are superior to the same model with a conventional, fixed depreciation rate.