Family structure and teenagers' reading ability

When people discuss academic attainment and disadvantage it tends, implicitly or explicitly, to be about economic disadvantage. This makes sense since socio-economic status (SES) is all too important a predictor of how young people do in the education system. But there are other dimensions worth thinking about.

One is family structure, which is generally understood to refer to which parents, if any, a child is living with. Using PISA data for Ireland, I graph the average reading score by a measure of family structure.

The four categories are “single”: living with a single parent or guardian (usually the mother), “nuclear” : living with mother & father, “mixed” : living with either a mother & male guardian (like a stepfather) or father/female guardian and “other”.

It is clear that children in nuclear families do best. The difference is statistically significant. While there are no controls here, the result is indeed robust when one allows for SES, the child’s sex and various other factors. This isn’t surprising as there is a fair amount of research on this matter looking in particular at the effects of single parenthood on childrens’ outcomes, for example the work by Sara McLanahan and Gary Sandefur.

One has to be very careful about jumping to policy recommendations from evidence such as this. It doesn’t follow that any particular family structure is “best” and people in non-nuclear families are often there for a good reason. What I think can be argued is that our educational system should take account those factors which are known to militate against young people achieving their full potential.

The data here was collected in 2000 but the same pattern would almost certainly show up in more recent waves of PISA or indeed any data on student achievement.

Time in the class and educational attainment: evidence from PISA

In the soul searching that has followed the release of the Leaving & Junior Certificate exams and particularly in the context of the maths results some commentators have pointed to the relatively low hours in class spent by Irish students. Does it actually matter? This paper shows that it does:

Do Differences in School's Instruction Time Explain International Achievement Gaps in Maths, Science and Language? Evidence from Developed and Developing Countries
Victor Lavy
There are large differences across countries in instructional time in schooling institutions. Can these differences explain some of the differences across countries in pupils' achievements in different subjects? What is the likely impact of changes in instructional time? While research in recent years provides convincing evidence about the effect of several inputs in the education production function, there is limited evidence on the effect of classroom instructional time. Such evidence is of policy relevance in many countries, and it became very concrete recently as President Barrack Obama announced the goal of extending the school week and year as a central objective in his proposed education reform for the US. In this paper, I estimate the effects of instructional time on students' academic achievement in math, science and language. I estimate linear and non-linear instructional time effects controlling for unobserved heterogeneity of both pupils and schools. The evidence from a sample of 15 year olds from over fifty countries that participated in PISA 2006 consistently shows that instructional time has a positive and significant effect on test scores. The effect is large relative to the standard deviation of the within pupil test score distribution. The OLS results are highly biased upward but the within student estimates are very similar across groups of developed and middle-income countries. However, the estimated effect of instructional time in the sample of developing countries is much lower than the effect size in the developed countries. Several checks for threats of identification support the causal interpretation of this evidence. I obtain very similar results when I use as an alternative data from primary and middle schools in Israel and a somewhat different identification strategy