Twinning Rates in Developed Countries: Trends and Explanations

The twinning rate has increased dramatically over the last four decades in developed countries. Two main factors account for this increase: delayed childbearing, as older women tend to have twins more frequently than younger ones, and the expansion of medically assisted reproduction (MAR), which carries an increased probability of multiple births. Using civil registration data, we estimate the share of the increase in twinning rates attributable to the rise in the age at childbearing and to MAR. The effect of MAR is estimated to be about three times as important as the effect of delayed childbearing. Negative health outcomes associated with multiple births and the cost of MAR have raised concerns. We find that in one‐quarter of developed countries with the relevant data, the twinning rate reached a plateau around the early 2000s and decreased thereafter. We examine the reasons for this reversal, in particular changes in MAR policies and practices.     

The Co-pay in Dutch Health Care: Policy and Effectiveness

This article describes the results of an empirical study into the design and effectiveness of the co-pay in Dutch Health care. With a reconstruction of the policy theory and the application of "the instrument theory" of Bressers and Klok, we are able to predict that the co-pay would not be effective. A process evaluation and an effect evaluation show that this is indeed the case. Not surprisingly, the second Kok administration determined that the instrument would be terminated.     

For Better and for Worse: The Relationship Between Union Dissolution and Self-Assessed Health in European Panel Data

We investigate the association between union dissolution and self-assessed health in European panel data. Previous studies suggest that this association might be negative, yet it is unclear to what extent this reflects causation (an effect of union dissolution of health) and/or selection (an effect of health on union dissolution). We analyzed the relationship between self-assessed health and 3,894 union dissolutions in about 60,000 respondents aged 18–59 across eight waves of the European Community Household Panel (ECHP). Fixed-effect panel analyses show that the negative association between dissolution and self-assessed health is not due to a general negative effect of divorce on health. Rather, after union dissolution self-assessed health improves among some individuals, while for others it declines. Compared to being in a union continuously, union dissolution seems to cause increases and decreases in health. We also find evidence for a negative effect of self-assessed health on dissolution risks. This selection effect appears to be associated with being in poor self-assessed health for a prolonged period of time rather than by the immediate effect of a health decline. Our results support the idea that the association between union dissolution and self-assessed health is an outcome of both causation and selection and that the effect of union dissolution on self-assessed health is heterogeneous.     

Do Measured and Unmeasured Family Factors Bias the Association Between Education and Self-Assessed Health?

The association between educational attainment and self-assessed health is well established but the mechanisms that explain this association are not fully understood yet. It is likely that part of the association is spurious because (genetic and non-genetic) characteristics of a person’s family of origin simultaneously affect one’s educational attainment and one’s adult health. In order to obtain an unbiased estimate of the association between education and health, we have to control for all relevant family factors. In practice, however, it is impossible to measure all relevant family factors. Sibling models are particularly appropriate in this case, because they control for the total impact of family factors, even if not all relevant aspects can be measured. I use data on siblings from a US study (MIDUS) and Dutch study (NKPS) to assess the total family impact on self-assessed health and, more importantly, to assess whether there is a family bias in the association between educational attainment and self-assessed health. The results suggest that there is a substantial family effect; about 20% of the variation in self-assessed health between siblings can be ascribed to (measured and unmeasured) family factors. Measured family factors, such as parental education and father’s occupation, could account only for a small part of the family effect. Furthermore, the results imply that it is unlikely that there is substantial bias due to family effects in the association between education and self-assessed health. This strengthens the conclusions from prior studies on the association between education and self-assessed health.     

Are the Negative Effects of Divorce on Well‐Being Dependent on Marital Quality?

We test the so‐called escape hypothesis, which argues that for people from a poor marriage, a divorce has a less negative or even a positive effect on well‐being. In an analysis of two waves of the National Survey of Families and Households (N =4,526), we find only limited evidence. When people divorce from a dissatisfactory or unfair marriage, they experience smaller increases in depression than when they divorce from a less dissatisfactory and less unfair marriage. For marital conflict, we find no interaction. Marital aggression seems to increase the negative effect of divorce, especially among women, suggesting that notions about the accumulation of problems after divorce need to be considered in combination with notions of escape.     

Positivity conditions for stochastic state space modelling of time series

This short paper clarifies some aspects of the balancing method for state space modelling of observed time series. This method may fail to satisfy the so-called positive real condition for stochastic processes. We illustrate this by theoretical spectral analysis and also by simulating univariate ARMA (1,1) models.     

Childlessness and Development in Sub-Saharan Africa: Is There Evidence for a U-shaped Pattern?

European Journal of Population - In high-income countries, women increasingly remain permanently childless. Little is known about the relationship between childlessness and socioeconomic...     

Family Size and Parental Wealth: The Role of Family Transfers in Europe

European Journal of Population - As baby boomers enter retirement, an increasing portion of the population in Europe will rely on wealth as a source of financial security. We address two research...