5(30)
siblings of the same gender but with a different birth order. We know that
firstborn children in general are more prosperous on the labour market
than their younger siblings and that this difference is not biologically
determined.
7
Here we ask whether siblings of the same gender differ in
their sickness absence depending on their birth order and whether this
potential birth-order effect varies in magnitude depending on the parents’
level of sick leave.
The analysis is based on register data covering all Swedish citizens in the
age range of 16 to 65 years. The parents are observed between 1986 and
1991 when their children are between 10 and 19 years old. The children
are observed between 2003 and 2008. By sick leave we mean the number
of days’ entitled sickness benefit or disability pension received from the
Swedish Social Insurance.
8
The main result is that there is a positive correlation between parents’
and their children’s rates of sick leave. The magnitude of this correlation is
about the same irrespective of the gender of the parent and the child. The
child’s expected rate of sick leave increases with the parent’s rate, and the
intergenerational transmission is particularly strong from the parents with
the highest rates of sick leave. Furthermore, there seems to be a threshold
effect in the sense that if the parent takes any sick leave, the child’s
expected number of sick leave days is almost 50 per cent higher than if the
parent lacks sick leave days. We also find a positive correlation between
the children’s sick leave rate and the sick leave rate of their parents-in-law,
indicating that persons tend to live with a partner who resembles their
parents with respect to sick leave.
Finally, we find that firstborn daughters report less sick leave than their
younger siblings of the same gender. However, this sibling gap only
emerges in the group of daughters with parents who lack sick leave
themselves, suggesting that the birth-order effect is only of importance
for explaining sick leave among women with low levels of sick leave.
This paper has the following structure. Section 2 describes the potential
mechanisms behind intergenerational transmission of sickness absence.
Section 3 contains an overall description of the social insurance system in
Sweden. Section 4 presents the empirical strategy, sections 5 to 7 present
the results and section 8 concludes the paper.
7
Firstborn children tend to have slightly more education and a higher income than
their younger siblings (Black, Devereux and Salvanes, 2011; Sulloway, 2007) and
this seems not to be biologically determined (Kristensen and Bjerkedal, 2007) or
affected by family breakdown (Black, Devereux and Salvanes, 2011).
8
Sickness benefit is used more temporarily than disability pension. However, long-
term sickness absence with sickness benefit often results in absence spells with a
disability pension. The aim here is to capture all types of absence due to sickness
rather than the type of benefit.
