اصطکاک های بازار کار و بازده تولید در مدارس دولتی  Labor Market Frictions and Production Efficiency in Public Schools

8. Conclusion We study the effect on student achievement when a school‟s local-area labor market is bisected by a state boundary. We find robust and highly-localized negative effects of intense exposure to a state boundary on the order of 0.09 school-level standard deviations of grade-8 math test scores. In reading, we find smaller negative effects that are only sometimes statistically significant. Our estimates can be converted into student-level standard deviations, which are more commonly used in education research, by multiplying them by roughly one-third (Bhatt and Koedel, 2012; Burgess, Wilson and Worth, 2013). Although the boundary effects are small on a per-student basis, they are spread across a very large population: based on the Common Core of Data, westimate that roughly 670,000 students are enrolled in middle schools nationally that are coded as “intensely affected” by a state boundary in our study. Labor frictions at state boundaries are a plausible explanation for our findings. A large literature in economics documents the adverse effect of labor frictions on production (Botero et al., 2004; Caballero et al., 2013; Haltiwanger, Scarpetta and Schweiger, 2006; Helpman and Itskhoki, 2010; Lafontaine and Sivadasan, 2009; Mitra and Ranjan, 2010) and explicit state policies make it costly for educators to cross state lines. Our empirical results are consistent with what would be predicted by economic theory in this regard. We also note that while we put forth state-specific pension and licensing policies as the most likely factors driving frictions in teacher labor markets near state boundaries, other state policies may also create frictions. Possibilities include aforementioned differences across states in teacher salaries and tax policies, among others. We attempted to examine heterogeneity in boundary effects along these dimensions, but our heterogeneity analyses are underpowered. One might also hypothesize that boundary effects on achievement will be more pronounced where labor markets are inherently thin, such as high school math and science teachers. Unfortunately, comprehensive testing data are not currently available on a national level to test for effects in higher grades where some types of labor may be particularly scarce.1