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Using Brazilian data, we estimate the impact of commuting duration on students' performance using distance to closest schools as an instrumental variable. In addition, we also use identification through heteroskedasticity, which does not rely on exclusion restrictions, and estimate bounds for the treatment effect in case there is remaining bias from unobservables. We find strong and consistent evidence that duration of commuting has a negative causal effect on academic achievement. Moreover, the relatively small heterogeneity across quantiles of test score makes us believe that public transportation policies targeted at students can promote education not only for those less well‐off. 相似文献
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Thierry Aubry Luca Antonio Dimuccio M. Mercè Bergadà Jorge Davide Sampaio Farid Sellami 《Journal of archaeological science》2010
The pre-Magdalenian phase of the Côa River Valley open-air rock art is mostly distributed at the boundary between the rocky valley slopes and the floodplain that correspond to the most favourable geomorphological setting for the preservation of pecked and deeply superposed engravings of the most famous artistic phase of the area. The natural vertical panels of the engraved art located at this geomorphological interface have suffered weathering during two cold events of the Lateglacial. They were buried by several colluvial and alluvial deposits. The reconstruction of the sedimentary and archaeological context of the CôaRiver Valley engraving permits a better assessment of the preservation processes and interpretation of Palaeolithic open-air rock art. 相似文献
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