Christiaan W. S. Monden

Twinning across the Developing World

Background Until now, little was known about the variation in incidence of twin births across developing countries, because national representative data was lacking. This study provides the first comprehensive overview of national twinning rates across the developing world on the basis of reliable survey data. Methods Data on incidence of twinning was extracted from birth histories of women aged 15–49 interviewed in 150 Demographic and Health Surveys, held between 1987 and 2010 in 75 low and middle income countries. During the interview, information on all live births experienced by the women was recorded, including whether it was a singleton or multiple birth. Information was available for 2.47 million births experienced by 1.38 million women in a period of ten years before the interview. Twinning incidence was measured as the number of twin births per thousand births. Data for China were computed on the basis of published figures from the 1990 census. Both natural and age-standardized twinning rates are presented. Results/Conclusions The very low natural twinning rates of 6–9 per thousand births previously observed in some East Asian countries turn out to be the dominant pattern in the whole South and South-East Asian region. Very high twinning rates of above 18 per thousand are not restricted to Nigeria (until now seen as the worlds twinning champion) but found in most Central-African countries. Twinning rates in Latin America turn out to be as low as those in Asia. Changes over time are small and not in a specific direction. Significance We provide the most complete and comparable overview of twinning rates across the developing world currently possible.

Length of life inequality around the globe

Inequality in the distribution of adult length of life - defined as age at death in the population aged 15 and over - is studied for virtually all countries of the world using a new database with over 9000 life tables covering a period of up to two centuries. The data reveal huge variation among countries and time periods in the degree to which the available years of life are distributed equally among the population. Most length of life inequality (about 90%) is within-country inequality. Our findings make clear that measures of length of life inequality should be adjusted for life expectancy to get a more relevant indicator of length of life differentials across populations. At similar levels of life expectancy, substantial differences in inequality are observed, even among highly developed countries. Expressed as premature mortality, inequality may be 35-70% higher in the most unequal countries compared to the most equal ones. Countries that reached a certain level of life expectancy earlier in time than other countries, and countries that improved their life expectancy more quickly than others, experienced higher levels of inequality.

Maternal height and child mortality in 42 developing countries

Previous research reports mixed results about the association between maternal height and child mortality. Some studies suggest that the negative association might be stronger in contexts with fewer resources. This hypothesis has yet not been tested in a cross‐nationally comparative design. We use data on 307,223 children born to 194,835 women in 444 districts of 42 developing countries to estimate the association between maternal height and child mortality and test whether this association is modified by indicators at the level of the household (like sex, age and twin status of the child and socio‐economic characteristics of the mother and her partner), district (regional level of development, public health facilities and female occupational attainment) and country (GDP per capita). We find a robust negative effect of logged maternal height on child mortality. The effect of maternal health is strongest for women with least education and is more important in the first year after birth and for twin births. The indicators of development at the district and country level do not modify the effect of maternal height. Am. J. Hum. Biol. 2009.

Ethnic Intermarriage in Times of Social Change: The Case of Latvia

We gain insight into the dynamics of ethnic intermarriage in times of social change by studying marriages between Latvians and Russians (including Belarussians and Ukrainians) that occurred in Latvia before and after independence from the Soviet Union. Before independence, ethnic intermarriage was already rather common, involving about 17% of the marriages annually. Since independence, intermarriage between Russians and Latvians has increased substantially. Part of this increase can be explained by selective emigration, but at least half of it may be due to integrative processes. Although there were more marriages between Russian men and Latvian women before independence, the gender pattern reversed after independence. Intermarriage levels were the highest among the less educated, children of mixed couples, partners with similar educational levels, and people in the countryside.

Does education buffer the impact of disability on psychological distress

This paper investigates whether education buffers the impact of physical disability on psychological distress. It further investigates what makes education helpful, by examining whether cognitive ability and occupational class can explain the buffering effect of education. Two waves of the 1958 British National Child Development Study are used to test the hypothesis that the onset of a physical disability in early adulthood (age 23 to 33) has a smaller effect on psychological distress among higher educated people. In total 423 respondents (4.6%) experienced the onset of a physical disability between the ages of 23 and 33. We find that a higher educational level cushions the psychology impact of disability. Cognitive ability and occupational class protect against the effect of a disability too. The education buffer arises in part because individuals with a higher level of education have more cognitive abilities, but the better social position of those with higher levels of education appears to be of greater importance. Implications of these findings for the social gradient in health are discussed.

Marriage Timing over the Generations

Strong relationships have been hypothesized between the timing of marriage and the familial environment of the couple. Sociologists have identified various mechanisms via which the age at marriage in the parental generation might be related to the age at marriage of the children. In our paper we study this relationship for historical populations. We use a dataset consisting of several hundreds of thousands of marriages contracted in three of the 11 Dutch provinces between 1812 and 1922. We identified the generational links between the brides, grooms, their parents, and grandparents. We studied (a) whether there is a relationship between ages at marriage of (grandfathers) fathers and sons, and ages at marriage of (grandmothers) mothers and daughters and (b) whether this relationship might be explained by social class. We find evidence for a clear effect of the family on age at marriage and substantial intergenerational transmission. The impact that the family of origin has on age at entry into marriage can partly be attributed to social class. We also observed positive effects of grandparents’ age at marriage on their offspring’s age at marriage.

The division of labor and depressive symptoms at the couple level: Effects of equity or specialization?

This paper studies the effect of the division of labor within households on husbands’ and wives’ depressive symptoms. Economic theory argues that specialization enhances mental health and wellbeing, whereas other, more psychological theories argue that equity matters most. We analyze data on husbands and wives from two waves of the National Survey of Families and Households. By combining information on the time spent on household and paid labor, we are able to construct separate and partly independent measures of equity and specialization. We find clear evidence for the equity hypothesis. When hours spent on paid and household labor are more equally distributed between husband and wife, both report fewer depressive symptoms. Only weak and inconsistent support was found for a positive effect of specialization.

Does the effect of job loss on psychological distress differ by educational level

We examine the impact of involuntary job loss on psychological distress and investigate whether the impact differs by educational level using a sample of men drawn from the British Household Panel Study. We expect higher-educated men to suffer less from job loss because they have more resources and better re-employment chances. Alternatively, it could be that, in the long run, lower-educated men adapt better to continued unemployment or downward mobility. Fixed effects regression analyses show that job loss increases distress, but over time the effect wears off and is limited to non-employed men. We find that higher-educated men experience less distress following job loss. These educational differences in the impact of job loss become smaller over time and are mainly driven by re-employment chances.

The importance of father’s and own education for self-assessed health across Europe: an East–West divide?

How are ones own education, fathers education, and especially the combination of the two, related to self-assessed health across European societies? In this study, we test hypotheses about differences in self-assessed health between 16 post-socialist countries in Central and Eastern Europe and 17 Western European countries. We find substantial cross-national variation in the (relative) importance of own and fathers education for self-assessed health. Over 65 per cent of this cross-national variation is accounted for by the East-West divide. This simple dichotomy explains cross-national differences better than gross domestic product or income inequality. An individuals fathers education is more important, both in absolute and relative terms, for self-assessed heath in Eastern Europe than in Western Europe. Intergenerational mobility moderates the relative effects of ones own and ones fathers education. In Eastern Europe the relative importance of ones fathers education is greater than it is in Western Europe--particularly for those who are downwardly mobile and have a father with tertiary education. The results are sometimes contradictory to initial expectations; the theoretical implications are discussed.

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.