The Effect of Usage and Size on Tractor Depreciation
通过计量模型分析拍卖拖拉机价格，发现车龄、使用小时数、尺寸和车况显著影响价格，实际折旧接近年数总和法，高使用强度对价值影响不大，但低年使用量的拖拉机在拍卖中溢价明显。
Abstract An econometric model was estimated to explain prices for tractors sold at auction. Tractor age, hours of use, size, and condition were statistically significant explanatory variables. Real tractor depreciation most closely approximated a sum‐of‐the‐years digits pattern. Tractors sold at consignment and bankruptcy auctions brought a lower price than tractors sold by retiring farmers. High levels of usage did not greatly reduce tractor value, but tractors with low annual usage brought substantial premiums in the auction market.