Israa Hashem

Does Having an Older Sister Matter? Sibling Sex, School Achievement, and Parental Investment

Children spend much of their time with siblings, yet how siblings affect achievement is far less studied than the role of parents, schools, and peers. I study whether the sex of an older sibling matters for how second-born children perform in school, using administrative records for British Columbia students linked to the Canadian Census. Because the sex of the firstborn is not chosen by parents, it provides a quasi-random source of variation in the sibling environment in which a child grows up. My empirical strategy compares second-born children with an older sister to those with an older brother within the same school district and assessment year. I find positive effects on literacy: Grade 4 reading and writing scores rise by 2.3 and 1.6 percent of a standard deviation, the effects persist into Grade 7, and numeracy is unaffected. Parents also respond: an older sister raises French immersion participation, a program that places children on a distinct educational path, by about 1.5 percentage points. Since second-borns score below their firstborn siblings, an older sister appears to compensate for part of this birth-order penalty. These findings suggest that sibling composition, and not only family background, can shape children's learning and parents' investments in their schooling.

Intergenerational Educational Mobility and Field-of-Study Choice in Immigrant and Canadian-Born Families

Immigrant parents in Canada are highly educated and concentrated in STEM fields, but do their children follow the same paths? I use the Survey of Labour and Income Dynamics to examine intergenerational degree attainment. Educational persistence is strong overall. However, it is weaker for children of immigrant fathers, suggesting greater mobility among second-generation immigrants. First-generation immigrants sort clearly into STEM, yet this sorting does not carry over to the second generation, whose degree choices converge with those of the Canadian-born. These findings have implications for how immigration shapes Canada's skill composition over time.

When Does a Stable and Pareto-Efficient Matching Exist?

with Szilvia Pápai

We study when a matching market has an outcome that is both stable and Pareto efficient. The question arises naturally in school choice and other priority-based allocation problems, where stability and participant welfare are both central objectives. These objectives can diverge substantially: even the student-optimal stable matching may leave large welfare improvements available to students. We develop constructive procedures that use the market's preferences and priorities to determine exactly when stability and Pareto efficiency are compatible. Our main procedure builds the matching step by step and succeeds exactly when a stable and Pareto-efficient matching exists. The results are also relevant for markets using deferred-acceptance-type procedures, where they identify when the resulting matching is already Pareto efficient for the students.