A critical question in education policy is whether seasonal migrant students have negative spillovers on the school performance of their peers. Negative spillovers may result if teachers in schools with large seasonal migrant populations are unable to address the needs of all students, especially if migrant students must catch up on the curriculum or if they have different learning styles. Language barriers, disciplinary problems, or difficulties establishing relationships with migrant peers might also hinder learning. On the other hand, students could benefit from larger migrant populations if migrant students exhibit better than average classroom behavior or if school administrators react to an influx of seasonal migrants by increasing classroom resources.

Carrell and Charlton investigate whether the proportion of migrant students within a school and grade affects school performance of non-migrant and migrant students. Researchers are collecting panel data to compare student outcomes of different cohorts over time within the same school as in Carrell & Hoekstra (2009). They are using the number of local cropland acres left fallow due to low water supply as an instrument for the migrant share of student enrollment at nearby elementary schools. These crop data will be combined with school-grade-year test score data to determine how exogenous changes in the number of migrant peers affect student outcomes.