Does coresidence with grandparents reduce the negative association between sibship size and reading test scores? Evidence from 40 countries

This paper investigates the effect of coresidence with grandparents in three-generation households on the nature and size of the association between sibship size and reading test scores. It also explores whether this interaction changes with the level of socioeconomic development of a society. We argue that coresidence in traditional three-generation households has a protective effect against resource dilution and thus decreases the magnitude of the negative association between family size and test scores. We also suggest that coresidence in more modern contexts magnifies the degree of this negative association, since modern families form three-generation households only when severely destabilized. We apply 3-level regression models to the PISA 2000 data to examine our hypotheses and use the Human Development Index as a measure of development. We find that the negative association between family size and test scores increases at higher levels of development and does so more strongly when students coreside with grandparents. We, however, find no context, in which coresidence would erase the negative consequences of having many brothers and sisters on one's own school test scores. These findings hold even when controlling statistically for the effects of public expenditure on education, public social security expenditure, and crude divorce rate as well as for the interactions of these variables with sibship size.