Identifying Human-Capital Externalities: Theory with Applications
指出现有方法混淆了正外部性与工资变化，提出一种新方法识别人力资本外部性，并应用于1970-1990年美国城市和州的数据，未发现显著的平均教育外部性。
The identification of aggregate human-capital externalities is still not fully understood. The existing (Mincerian) approach confounds positive externalities with wage changes due to a downward sloping demand curve for human capital. As a result, the Mincerian approach yields positive externalities even when wages equal marginal social products. We propose an approach that identifies human-capital externalities, whether or not aggregate demand for human capital slopes downward. Another advantage of our approach is that it does not require estimates of the individual return to human capital. Applications to U.S. cities and states between 1970 and 1990 yield no evidence of significant average-schooling externalities. Copyright 2006, Wiley-Blackwell.