Mikko Myrskylä

Advances in development reverse fertility declines

During the twentieth century, the global population has gone through unprecedented increases in economic and social development that coincided with substantial declines in human fertility and population growth rates. The negative association of fertility with economic and social development has therefore become one of the most solidly established and generally accepted empirical regularities in the social sciences. As a result of this close connection between development and fertility decline, more than half of the global population now lives in regions with below-replacement fertility (less than 2.1 children per woman). In many highly developed countries, the trend towards low fertility has also been deemed irreversible. Rapid population ageing, and in some cases the prospect of significant population decline, have therefore become a central socioeconomic concern and policy challenge. Here we show, using new cross-sectional and longitudinal analyses of the total fertility rate and the human development index (HDI), a fundamental change in the well-established negative relationship between fertility and development as the global population entered the twenty-first century. Although development continues to promote fertility decline at low and medium HDI levels, our analyses show that at advanced HDI levels, further development can reverse the declining trend in fertility. The previously negative development–fertility relationship has become J-shaped, with the HDI being positively associated with fertility among highly developed countries. This reversal of fertility decline as a result of continued economic and social development has the potential to slow the rates of population ageing, thereby ameliorating the social and economic problems that have been associated with the emergence and persistence of very low fertility.

Happiness: Before and After the Kids

Understanding how having children influences parents’ subjective well-being (“happiness”) has great potential to explain fertility behavior. We study parental happiness trajectories before and after the birth of a child, using large British and German longitudinal data sets. We account for unobserved parental characteristics using fixed-effects models and study how sociodemographic factors modify the parental happiness trajectories. Consistent with existing work, we find that happiness increases in the years around the birth of a first child and then decreases to before-child levels. Moreover, happiness increases before birth, suggesting that the trajectories may capture not only the effect of the birth but also the broader process of childbearing, which may include partnership formation and quality. Sociodemographic factors strongly modify this pattern. Those who have children at older ages or who have more education have a particularly positive happiness response to a first birth; and although having the first two children increases happiness, having a third child does not. The results, which are similar in Britain and Germany, suggest that having up to two children increases happiness, and mostly for those who have postponed childbearing. This pattern is consistent with the fertility behavior that emerged during the second demographic transition and provides new insights into low and late fertility.

Always the Third Rail? Pension Income and Policy Preferences in European Democracies

Social transfer programs are thought to generate beneficiary groups who will act politically to defend “their” programs from retrenchment. But little empirical research has been conducted to either verify or disconfirm the micro foundations of this hypothesis, which lies at the heart of the “new social risks” thesis as well as many economic analyses of welfare state politics. This article tests empirically whether benefiting from public pensions leads individuals to greater support of the pension system status quo, net of other factors. It uses cross—data set imputation to combine cross-nationally comparable individual-level data on income from public pensions with political attitudes toward proposed pension reforms. The hypothesis that public pension systems create policy feedbacks of self-interested beneficiaries supporting further pension spending is not supported in any of 11 European countries in either 1992 or 2001.

Weight change, initial BMI, and mortality among middle- and older-aged adults

Background: It is not known how the relationship between weight change and mortality is influenced by initial body mass index (BMI) or the magnitude of weight change. Methods: We use the nationally representative Health and Retirement Study (n = 13,104; follow-up 1992–2006) and Cox regression analysis to estimate relative mortality risks for 2-year weight change by initial BMI among 50- to-70-year-old Americans. We defined small weight loss or gain as a change of 1–2.9 BMI units and large weight loss or gain as a change of 3–5 BMI units. Results: Large and small weight losses were associated with excess mortality for all initial BMI levels below 32 kg/m2 (eg, hazard ratio [HR] for large weight loss from BMI of 30 = 1.61 [95% confidence interval = 1.31–1.98]; HR for small weight loss from BMI of 30 = 1.19 [1.06–1.28]). Large weight gains were associated with excess mortality only at high BMIs (eg, HR for large weight gain from BMI of 35 = 1.33 [1.00–1.77]). Small weight gains were not associated with excess mortality for any initial BMI level. The weight loss–mortality association was robust to adjustments for health status and to sensitivity analyses considering unobserved confounders. Conclusions: Weight loss is associated with excess mortality among normal, overweight, and mildly obese middle- and older-aged adults. The excess risk increases for larger losses and lower initial BMI. These results suggest that the potential benefits of a lower BMI may be offset by the negative effects associated with weight loss. Weight gain may be associated with excess mortality only among obese people with an initial BMI over 35.

Maternal age and offspring adult health: evidence from the health and retirement study.

Advanced maternal age is associated with negative offspring health outcomes. This interpretation often relies on physiological processes related to aging, such as decreasing oocyte quality. We use a large, population-based sample of American adults to analyze how selection and lifespan overlap between generations influence the maternal age–offspring adult health association. We find that offspring born to mothers younger than age 25 or older than 35 have worse outcomes with respect to mortality, self-rated health, height, obesity, and the number of diagnosed conditions than those born to mothers aged 25–34. Controls for maternal education and age at which the child lost the mother eliminate the effect for advanced maternal age up to age 45. The association between young maternal age and negative offspring outcomes is robust to these controls. Our findings suggest that the advanced maternal age–offspring adult health association reflects selection and factors related to lifespan overlap. These may include shared frailty or parental investment but are not directly related to the physiological health of the mother during conception, fetal development, or birth. The results for young maternal age add to the evidence suggesting that children born to young mothers might be better off if the parents waited a few years.

Income differences in life expectancy: the changing contribution of harmful consumption of alcohol and smoking.

Background: Social differences in mortality have increased in high-income countries, but the causes of these changes remain unclear. We quantify the contribution of alcohol and smoking to trends in income differences in life expectancy from 1988 through 2007 in Finland. Methods: An 11% sample from the population registration data of Finns 25 years and older was linked with an 80% oversample of death records. Alcohol-attributable mortality was based on underlying and contributory causes of death on individual death certificates and smoking-attributable mortality on an indirect method that used lung cancer mortality as an indicator for the impact of smoking on mortality. Results: Alcohol- and smoking-attributable deaths reduced life expectancy by about 4.5 years among men. Alcohol-attributable mortality increased and smoking-attributable mortality decreased over the period 1988–2007, leaving the joint contribution stable. Among women, the contribution of these risk factors to life expectancy over the same period increased from 0.7 to 1.2 years. In 2003–2007, life expectancy differentials between the lowest and highest income quintile were 11.4 years (men) and 6.3 years (women). In the absence of alcohol and smoking, these differences would have been 60% less for men and 36% less for women. Life expectancy differentials increased rapidly over the study period; without alcohol and smoking, the increase would have been 69% less among men and 85% less among women. Conclusions: Alcohol and smoking have a major influence on income differences in mortality and, with the exception of smoking among men, their contribution is increasing. Without alcohol and smoking, there would have been little change in life expectancy differentials.

Is Later Better or Worse? Association of Advanced Parental Age With Offspring Cognitive Ability Among Half a Million Young Swedish Men

Parental ages are increasing in the developed world, and postponed parenthood may have a negative association with the cognitive ability of offspring. There is, however, inconclusive evidence regarding the impact of both maternal and paternal ages. We have been able to reduce or eliminate unobserved confounding by using methods that account for fixed parental characteristics shared by brothers. Associations between parental age and intelligence quotient (IQ) among 565,433 Swedish males (birth cohorts 1951 to 1976) were analyzed, with IQ measured at conscription examinations (given between ages 17 and 20 years). When we accounted for the IQ time trend by adjusting for birth year, advanced paternal age showed no association with offspring IQ; however, maternal ages above 30 years were inversely associated with offspring IQ. For example, maternal ages 40-44 years were associated with an offspring IQ that was 0.07 standard deviations lower than that for maternal ages 25-29 years (P < 0.001). However, the IQ trend more than offset the impact of age, as without birth year adjustment, advanced maternal age was positively associated with IQ. Although the results confirmed that maternal age was negatively associated with offspring IQ, the association was small enough that delaying parenthood resulted in higher offspring IQ scores because of the positive IQ test score trend.

Socioeconomic status across the life course and all-cause and cause-specific mortality in Finland

We used high quality register based data to study the relationship between childhood and adult socio-demographic characteristics and all-cause and cause-specific mortality at ages 35-72 in Finland among cohorts born in 1936-1950. The analyses were based on a 10% sample of households drawn from the 1950 Finnish Census of Population with the follow-up of household members in subsequent censuses and death records beginning from the end of 1970 through the end of 2007. The strengths of these data come from the fact that neither childhood nor adult characteristics are self reported and thus are not subject to recall bias, misreporting and no loss to follow-up after age 35. In addition, the study population includes several families with at least two children enabling us to control for unobserved family characteristics. We documented significant associations between early life social and family conditions on all-cause mortality and cause-specific mortality, with protective effects of higher childhood socio-demographic characteristics varying between 10% and 30%. These associations were mostly mediated through adult educational attainment and occupation, suggesting that the indirect effects of childhood conditions were more important than their direct effects. We further found that adult socioeconomic status was a significant predictor of mortality. The associations between adult characteristics and mortality were robust to controls for observed and unobserved childhood characteristics. The results imply that long-term adverse health consequences of disadvantaged early life social circumstances may be mitigated by investments in educational and employment opportunities in early adulthood.

Advanced Maternal Age and Offspring Outcomes: Reproductive Aging and Counterbalancing Period Trends

Advanced Maternal Age and Offspring Outcomes : Reproductive Aging and Counterbalancing Period Trends

Lifespan variation by occupational class: compression or stagnation over time?

Cross-sectional analyses of adult lifespan variation have found an inverse association between socioeconomic position and lifespan variation, but the trends by social class are unknown. We investigated trends in lifespan variation over four decades (1971–2010) by occupational social class (manual, lower nonmanual, upper nonmanual, other) using Finnish register data. We performed age and cause-of-death decompositions of lifespan variation for each sex (a) by occupational class over time and (b) between occupational classes at a shared level of life expectancy. Although life expectancy increased in all classes, lifespan variation was stable among manual workers and decreased only among nonmanual classes. These differences were caused by early-adult mortality: older-age lifespan variation declined for all the classes, but variation in early-adult mortality increased for all classes except the highest. The manual class’s high and stagnant lifespan variation was driven by declines in circulatory diseases that were equally spread over early mortality-compressing and older mortality-expanding ages, as well as by high early-adult mortality from external causes. Results were similar for men and women. The results of this study, which is the first to document trends in lifespan variation by social class, suggest that mortality compression is compatible with increasing life expectancy but currently achieved only by higher occupational classes.