Estimating Duality Models with Biased Technical Change: A Time Series Approach
指出技术变化是计量模型中的遗漏变量，用时间趋势代表技术变化可能不恰当。作者用时间序列方法估计加拿大中部的成本函数，发现要素份额、价格和产出存在协整关系，表明技术变化是中性的；而用时间趋势则会错误地得出技术变化有偏的结论。
Abstract Technical change is an omitted variable in econometric models which estimate technical change biases with no direct measure of this variable. Modeling technical change as a deterministic time trend is a restrictive representation that may be inconsistent with the type of nonstationarity of the other model variables. We used a time‐series approach to estimate a cost function for central Canada and found that factor shares, prices, and output are cointegrated, implying that technical change is neutral. In contrast, estimating the system with a time trend as a technical change measure leads one to conclude inappropriately that technical change biases exist.