National independence, women's political participation, and life expectancy in Norway

Male twinning after the 2008 Obama election: A test of symbolic empowerment

On November 4, 2008, Barack Obama was elected the first Black President of the United States. His campaign and electoral win served as a symbol of hope for a more just future, fostering an "Obama effect" that appears associated with improved well-being among non-Hispanic (NH) Black communities. Situating the Obama election within the symbolic empowerment framework, we consider the potentially protective role of the Obama election on NH Black fetal death, an important but understudied measure of perinatal health that has stark racial disparities. Using restricted-use natality files from the National Center for Health Statistics, we proxy fetal death using the male twin rate (number of twins per 1000 male live births). Male twins have a relatively high risk of in utero selection that is sensitive to maternal and environmental stressors, making the twin rate an important marker of fetal death. We then estimate interrupted time-series models to assess the relation between the Obama election and male twin rates among NH Black births across monthly conception cohorts (February 2003-October 2008). Greater-than-expected male twin rates signal less susceptibility to fetal loss. Results indicate a 4.5% higher male twin rate among all NH Black cohorts exposed in utero to the Obama election, after accounting for historical and NH white trends (p < 0.005). The greater-than-expected rates concentrated among births conceived in the months preceding Obama's nomination at the Democratic National Convention and Obama's presidential win. These results suggest a salutary perinatal response to election events that likely reduced NH Black fetal loss. They also indicate the possibility that sociopolitical shifts can mitigate persisting NH Black-NH white disparities in perinatal health.

Long-run intergenerational health benefits of women empowerment: Evidence from suffrage movements in the US

An ongoing body of research documents that women empowerment is associated with improved outcomes for children. However, little is known about the long-run effects on health outcomes. This paper adds to this literature and studies the association between maternal exposure to suffrage reforms and children's old-age longevity. We utilize changes in suffrage laws across US states and over time as a source of incentivizing maternal investment in children's health and education. Using the universe of death records in the US over the years 1979-2020 and implementing a difference-in-difference econometric framework, we find that cohorts exposed to suffrage throughout their childhood live 0.6 years longer than unexposed cohorts. Furthermore, we show that these effects are not driven by preexisting trends in longevity, endogenous migration, selective fertility, and changes in the demographic composition of the sample. Additional analysis reveals that improvements in education and income are candidate mechanisms. Moreover, we find substantial improvements in early-adulthood socioeconomic standing, height, and height-for-age outcomes due to childhood exposure to suffrage movements. A series of state-level analyses suggest reductions in infant and child mortality following suffrage law change. We also find evidence that counties in states that passed the law experienced new openings of County Health Departments and increases in physicians per capita.

Transitions that Matter? Czechoslovakia's Break up and Human Stature

Changes in a population’s average stature are virtuous pointers of wellbeing which are sensitive to improvements in psychosocial environments during childhood. A major structural change that could have altered an environment during childhood is the transition from communist to a liberal democracy, and, more specifically, the meltdown of the Soviet bloc provides for a quasi-natural experiment. This paper examines the trends in heights in the Czech Republic and Slovakia before and after the transition and the subsequent break-up of the Czechoslovakian federation. We find that one additional year of exposure to a liberal democracy while growing up is associated with an increasing population stature of 0.28 cm among Slovaks and 0.15 cm among Czechs. We only find changes in stature among men who are more sensitive to environmental stress, especially at the lower end of the current socio-economic status. Results are robust to alternative datasets and measures of democracy.

Racial/ethnic disparities in children's emergency mental health after economic downturns

African American children-more than other race/ethnicities-rely on emergency psychiatric care. One hypothesized cause of this overrepresentation involves heightened sensitivity to economic downturns. We test whether the African American/white difference in psychiatric emergency visits increases in months when the regional economy contracts. We applied time-series methods to California Medicaid claims (1999-2008; N = 7.1 million visits). One month following mass layoffs, African American youths use more emergency mental health services than do non-Hispanic whites. Economic downturns may provoke or uncover mental disorder especially among African American youth who by and large do not participate in the labor force.

The rise and fall of women's advantage: a comparison of national trends in life expectancy at age 65 years

The female advantage in life expectancy (LE) is found worldwide, despite differences in living conditions, the status of women and other factors. However, this advantage has decreased in recent years in low-mortality countries. Few researchers have looked at the gender gap in LE in old age (age 65) in a longer historical perspective. Have women always had an advantage in LE at old age and do different countries share the same trends? Life expectancy data for 17 countries were assessed from Human Mortality Database from 1751 to 2007. Since most of the changes in LE taking place today are driven by reductions of old age mortality the gender difference in LE was calculated at age 65. Most low-mortality countries show the same historical trend, a rise and fall of women’s advantage in LE at age 65. Three phases that all but two countries passed through were discerned. After a long phase with a female advantage in LE at 65 of <1 year, the gender gap increased significantly during the twentieth century. The increase occurred in all countries but at different time points. Some countries such as England and France had an early rise in female advantage (1900–1919), while it occurred 50 years later in Sweden, Norway and in the Netherlands. The rise was followed by a more simultaneous fall in female advantage in the studied countries towards the end of the century, with exceptions of Japan and Spain. The different timing regarding the increase of women’s advantage indicates that country-specific factors may have driven the rise in female advantage, while factors shared by all countries may underlie the simultaneous fall. More comprehensive, multi-disciplinary study of the evolution of the gender gap in old age could provide new hypotheses concerning the determinants of gendered differences in mortality.

Income gains and very low-weight birth among low-income black mothers in California

We test the hypothesis suggested in the literature that an acute income gain in the form of the earned income tax credit reduces the odds of a very low-weight birth among low-income non-Hispanic black mothers. We apply ecological time series and supplemental individual-level logistic regression methods to monthly birth data from California between 1989 and 1997. Contrary to our hypothesis, the odds of very low-weight birth increases above its expected value two months after mothers typically receive the credit. We discuss our findings in relation to the epidemiologic literature concerned with ambient events during pregnancy and recommend further investigation.

Hormonal evidence supports the theory of selection in utero

OBJECTIVES

Antagonists in the debate over whether the maternal stress response during pregnancy damages or culls fetuses have invoked the theory of selection in utero to support opposing positions. We describe how these opposing arguments arise from the same theory and offer a novel test to discriminate between them. Our test, rooted in reports from population endocrinology that human chorionic gonadotropin (hCG) signals fetal fitness, contributes not only to the debate over the fetal origins of illness, but also to the more basic literature concerned with whether and how natural selection in utero affects contemporary human populations.

METHODS

We linked maternal serum hCG measurements from prenatal screening tests with data from the California Department of Public Health birth registry for the years 2001-2007. We used time series analysis to test the association between the number of live-born male singletons and median hCG concentration among males in monthly gestational cohorts.

RESULTS

Among the 1.56 million gestations in our analysis, we find that median hCG levels among male survivors of monthly conception cohorts rise as the number of male survivors falls.

RESULTS

Elevated median hCG among relatively small male birth cohorts supports the theory of selection in utero and suggests that the maternal stress response culls cohorts in gestation by raising the fitness criterion for survival to birth.

Transient cultural influences on infant mortality: Fire-Horse daughters in Japan

OBJECTIVES

Parental investment theory suggests that the quality and quantity of parental care depends, in part, on assessments of whether offspring will survive and yield grandchildren. Consistent with this theory, we hypothesize that parental perception that a birth cohort will have low reproductive success coincides with higher than expected infant mortality in the cohort. We test this hypothesis in industrialized Japan in 1966 when cultural aversion to females born in the astrological year of the Fire-Horse may have jeopardized the life of female infants.

METHODS

We applied time-series methods to cohort infant mortality data for Japan, from 1947 to 1976, to test whether female infant mortality in 1966 rose above levels expected from history, male infant mortality, and fertility. Methods control for the secular decline in infant mortality as well as other temporal patterns that could induce spurious associations.

RESULTS

Findings support the hypothesis in that female infant mortality rises by 1.1 deaths per 1,000 live births above expected levels (coefficient = 0.0011; standard error = 0.0005; P = 0.03). The result indicates an excess of 721 female infant deaths statistically attributable to the Fire-Horse year. Findings remain robust to control for male infant mortality and the secular decline in mortality over the test period.

CONCLUSIONS

The discovery of a predictable, acute increase in female infant mortality during the Fire-Horse year supports the relevance of parental investment theory to developed countries. Results should encourage further research on the health sequelae of abrupt, population-level shifts in culture.

Selection in utero contributes to the male longevity deficit

The literature offering evolutionary explanations of the male longevity deficit does not address temporal variation in the deficit. This circumstance appears attributable to the fact that natural selection intuitively explains the deficit's pervasive and persistent nature, while social processes more parsimoniously explain its temporal variability. I offer consilience of these perspectives by speculating that selection in utero, a mechanism both conserved by natural selection and affected by social processes, could induce deviations around trend in the male longevity deficit. I describe the mechanism and offer an empirical test of its possible effect among Swedes - a population with the longest continuous record of sex-specific longevity in annual birth cohorts. I replicate the test with data from England and Wales. Results support the hypothesis that selection in utero against less fit males may explain part of the difference in longevity between males and females in modern populations.