Sibling Spillovers (WP-17-04)
Sandra Black, Sanni Breining, David Figlio, Jonathan Guryan, Krzysztof Karbownik, Helena Skyt Nielsen, Jeffrey Roth, Marianne Simonsen
It is notoriously difficult to identify peer effects within the family, because of the common shocks and reflection problems. The researchers make use of a novel identification strategy and unique data in order to gain some purchase on this problem. They employ data from the universe of children born in Florida between 1994 and 2002 and in Denmark between 1990 and 2001, which they match to school and medical records. To address the identification problem, the research team examines the effects of having a sibling with a disability. Utilizing three-plus child families, they employ a differences-in-differences research design which makes use of the fact that birth order influences the amount of time which a child spends in early childhood with their siblings, disabled or not. They observe consistent evidence in both locations that the second child in a family is differentially affected when the third child is disabled. The researchers also provide evidence which suggests that the sibling spillovers are working at least in part through the relative exposure to parental time and financial resources.