The Effect of Public Capital in State-Level Production Functions Reconsidered
利用美国48个州1970-1983年的面板数据，估计包含三类公共资本投入的柯布-道格拉斯生产函数，通过多种检验发现公共资本变量不显著，而固定效应和私人投入显著。
Using a panel data set for the forty-eight contiguous states from 1970 to 1983, several estimates are provided of a Cobb-Douglas production function with three types of public capital as inputs. Various specification tests are systematically applied to test for both random and fixed state effects, nonstationarity, endogeneity of the private inputs, and measurement error. In the preferred specification, which is first differences with fixed state effects, the public capital variables are not significant, while the fixed state effects and private input variables are significant. Copyright 1996 by MIT Press.