Estimating dynamic localization economies: the inadvertent success of the specialization index and the location quotient

摘要 评估动态的在地化经济：专殊化指标与区位商数无意中的成功。Regional Studies. 本文在处理集中与专殊化概念的定 义问题后，接着回顾在聚集经济的经验文献中使用的若干在地化经济指标的理由与诠释：专殊化指标与区位商数。 模拟操作显示出在什麽条件下，若干专殊化会导致动态在地化（马歇尔—MAR）外部性的偏差估计。研究结果显 示，应用研究者能够在地方产业，专殊化指标与区位商数中选择代理这些外部性，只要它们同时包含地方经济规模 的正确代理。

After addressing definitional issues on the concepts of concentration and specialization, the paper reviews the justifications for and the interpretation of some indicators of localization economies used in the empirical literature on agglomeration economies: specialization indexes and location quotients. A simulation exercise shows under what conditions certain specifications lead to biased estimations of dynamic localization (Marshall–Arrow–Romer – MAR) externalities. The results suggest that applied researchers can choose between the size of the local industry, the specialization index and the location quotient to proxy for these externalities as far as they also encompass a correct proxy for the size of the local economy