A propensity score matching method to study the achievement of students in upper secondary schools

In the paper, the achievement of students in the first year of the upper sec- ondary schools of the province of Bologna is investigated. In particular, we focus our attention on school location as potential causal factor influencing the outcome by comparing students from urban area schools with those from other towns of the province. We show that valid inference is assured by controlling for family back- ground whose influence on the outcome has been previously assessed.We employ a matching strategy based on propensity score to create treatment groups, correspond- ing to the values of the factor under study, with the same distribution of observed covariates. As a result, students are stratified in blocks according to the propensity score to obtain estimates of the average treatment effect using nearest neighbour matching. The role of family characteristics is further studied by testing whether the effect of school location on student achievements depends on number of siblings and educational qualification of the mother.