Right to Bear...
Patriarchal Policing of Sex in the Early United States
Mark Kann
Politics & Gender, September 2011, Pages 335-363
Abstract:
On the eve of the American Revolution, Benjamin Franklin published a satire instructing the British on humbling their American vassals. The British could castrate American males, thereby reducing American population growth. The logistics were simple: "Let a company of sow-gelders, consisting of 100 men, accompany the army. On their arrival at any town or village, let orders be given that on their blowing of the horn all the males be assembled in the market place. If the corps are men of skill and ability in their profession, they will make great dispatch, and retard but very little the progress of the army" (Franklin 1987, 718). Satire aside, Franklin's generation believed that sex and reproduction had a significant impact on the independence, strength, and durability of nations.
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The Earned Income Tax Credit and abortion
Chris Herbst
Social Science Research, November 2011, Pages 1638-1651
Abstract:
Using a panel of states between 1975 and 2005, I examine the relationship between the Earned Income Tax Credit (EITC) and abortion. Results suggest that increases in the EITC are associated with reductions in the overall abortion rate. Specifically, a $1000 increase in the maximum credit is associated with a 7.6% decrease in the overall abortion rate. This effect implies a reduction of approximately 1.6 abortions per 1000 women of childbearing age. I also provide evidence that the reduction in abortions is attributable to a drop in pregnancies, not an increase in the number of births. In other words, women appear to respond to increases in EITC generosity by altering sexual behavior, rather than shifting abortion-birth decisions after a pregnancy occurs.
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Influence of Valentine's Day and Halloween on Birth Timing
Becca Levy, Pil Chung & Martin Slade
Social Science & Medicine, October 2011, Pages 1246-1248
Abstract:
It is known that cultural representations, in the form of stereotypes, can influence functional health. We predicted that the influence of cultural representations, in the form of salient holidays, would extend to birth timing. On Valentine's Day, which conveys positive symbolism, there was a 3.6% increase in spontaneous births and a 12.1% increase in cesarean births. Whereas, on Halloween, which conveys negative symbolism, there was a 5.3% decrease in spontaneous births and a 16.9% decrease in cesarean births. These effects reached significance at p < .0001, after adjusting for year and day of the week. The sample was based on birth-certificate information for all births in the United States within one week on either side of each holiday across 11 years. The Valentine's-Day window included 1,676,217 births and the Halloween window included 1,809,304 births. Our findings raise the possibility that pregnant women may be able to control the timing of spontaneous births, in contrast to the traditional assumption, and that scheduled births are also influenced by the cultural representations of the two holidays.
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House Prices and Birth Rates: The Impact of the Real Estate Market on the Decision to Have a Baby
Lisa Dettling & Melissa Schettini Kearney
NBER Working Paper, October 2011
Abstract:
This project investigates how changes in Metropolitan Statistical Area (MSA)-level housing prices affect household fertility decisions. Recognizing that housing is a major cost associated with childrearing, and assuming that children are normal goods, we hypothesize that an increase in real estate prices will have a negative price effect on current period fertility. This applies to both potential first-time homeowners and current homeowners who might upgrade to a bigger house with the addition of a child. On the other hand, for current homeowners, an increase in MSA-level house prices might increase available home equity, leading to a positive effect on birth rates. Controlling for MSA fixed effects, trends, and time-varying conditions, our analysis finds that indeed, short-term increases in house prices lead to a decline in births among non-owners and a net increase among owners. Our estimates suggest that a 10 percent increase in house prices would lead to a 4 percent increase in births among home owners, and a roughly one percent decrease among non-owners. The net effect of house price changes on birth rates varies across demographic groups based on rates of home ownership. Our paper provides evidence that homeowners use some of their increased housing wealth, coming from increases in local area house prices, to fund their childbearing goals. More generally, the finding of a "home equity effect" demonstrates empirically that imperfect credit markets affect fertility timing.
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Deep Human Genealogies Reveal a Selective Advantage to Be on an Expanding Wave Front
Claudia Moreau et al.
Science, forthcoming
Abstract:
Since their origin, human populations have colonized the whole planet, but the demographic processes governing range expansions are mostly unknown. We analyzed the genealogy of more than 1 million individuals resulting from a range expansion in Quebec between 1686 and 1960 and reconstructed the spatial dynamics of the expansion. We find that a majority of the present Saguenay Lac Saint-Jean population can be traced back to ancestors having lived directly on or close to the wave front. Ancestors located on the front contributed significantly more to the current gene pool than those from the range core, likely due to a 20% larger effective fertility of women on the wave front. This fitness component is heritable on the wave front and not in the core, implying that this life-history trait evolves during range expansions.
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Evidence for evolution in response to natural selection in a contemporary human population
Emmanuel Milot et al.
Proceedings of the National Academy of Sciences, 11 October 2011, Pages 17040-17045
Abstract:
It is often claimed that modern humans have stopped evolving because cultural and technological advancements have annihilated natural selection. In contrast, recent studies show that selection can be strong in contemporary populations. However, detecting a response to selection is particularly challenging; previous evidence from wild animals has been criticized for both applying anticonservative statistical tests and failing to consider random genetic drift. Here we study life-history variation in an insular preindustrial French-Canadian population and apply a recently proposed conservative approach to testing microevolutionary responses to selection. As reported for other such societies, natural selection favored an earlier age at first reproduction (AFR) among women. AFR was also highly heritable and genetically correlated to fitness, predicting a microevolutionary change toward earlier reproduction. In agreement with this prediction, AFR declined from about 26-22 y over a 140-y period. Crucially, we uncovered a substantial change in the breeding values for this trait, indicating that the change in AFR largely occurred at the genetic level. Moreover, the genetic trend was higher than expected under the effect of random genetic drift alone. Our results show that microevolution can be detectable over relatively few generations in humans and underscore the need for studies of human demography and reproductive ecology to consider the role of evolutionary processes.
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Medication Abortions Among New York City Residents, 2001-2008
Cristina Yunzal-Butler, Judith Sackoff & Wenhui Li
Perspectives on Sexual and Reproductive Health, forthcoming
Context: Population-level research on trends in medication abortions and the association of patient characteristics and facility type with procedure choice is limited. Surveillance is necessary to ensure accurate reporting and understanding of service availability.
Methods: New York City induced abortion data for 2001-2008 were used to calculate medication abortion prevalence among women undergoing early abortions (i.e., at nine or fewer weeks of gestation). Multiple logistic regression analysis was used to assess associations between selected characteristics and having a medication, as opposed to surgical, abortion. Proportions of patients who went to clinics or hospitals that did not offer medication abortions were also calculated.
Results: Five percent of early abortions were medication procedures in 2001; the proportion rose to 13% by 2008. Eighty-two percent of medication abortions in 2008 were performed at freestanding clinics, and 10% at doctors' offices. The likelihood of having had a medication abortion, rather than a surgical one, was lower among blacks and Hispanics than among whites (odds ratios, 0.5 and 0.7, respectively). Medication abortions were more likely among women with more than 12 years of education than among those with less than a high school education (2.1), and more likely among those who went to doctors' offices than among clinic patients (3.6). Throughout 2001-2008, medication abortions were not available at 50% of hospitals and 31% of clinics that provided early abortions.
Conclusions: The increasing prevalence of medication abortions highlights the importance of active surveillance. Because many facilities do not offer the procedure, a better understanding of barriers to provision is needed.
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Silvia Josefina Venero Fernández et al.
American Journal of Epidemiology, forthcoming
Abstract:
The Trivers-Willard hypothesis suggests that populations respond to scarcity by decreasing the ratio of males to females at livebirth. Cuba experienced an extreme economic depression in the 1990s called the "special period." Using time-series analysis, the authors studied the impact of this event on the male:female sex ratio at birth in Cuba from 1960 to 2008. From 1990 to 1993, the per capita gross domestic product in Cuba decreased by 36%. By use of a definition of the special period from 1991 to 1998, there was a prolonged increase in the male:female ratio of livebirths during this period of economic depression (P < 0.001), from 1.06 at baseline to a peak of 1.18. This association persisted when using alternative definitions of the duration of economic depression in sensitivity analyses. Once the period of economic depression was over, the male:female ratio returned to the baseline value. These data suggest that, in Cuba, contrary to the Trivers-Willard hypothesis, the human population responded to conditions of scarcity by increasing the ratio of males to females at livebirth. These data may be relevant in the modeling of demographic projections in countries that experience prolonged economic depression and in understanding adaptive human reproductive responses to environmental change.
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Welfare state policy determinants of fertility level: A comparative analysis
Allison Rovny
Journal of European Social Policy, October 2011, Pages 335-347
Abstract:
One of the biggest demographic issues that many advanced industrialized countries face is the persistence of low fertility rates. Declining fertility rates pose potential obstacles to economic growth. Government budgets have to accommodate more pension and health services as the number of adults of working age who contribute to older generations' pensions diminishes. In this paper, I examine the determinants of fertility rates at the national level of 17 Organization for Economic Co-operation and Development (OECD) countries. Specifically, I perform a pooled time-series analysis covering the time period 1990-9. The analysis yields evidence that the types of state policies - active labor market programs, family-friendly policies and employment protection laws - play a significant role in either helping or hindering fertility levels. I find that active labor market policies and generous work and family policies encourage higher fertility rates, while the presence of employment protection legislation - rules concerning hiring and firing - hinders the growth of fertility rates.
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Where Have All the Young Men Gone? Using Gender Ratios to Measure Fetal Death Rates
Nicholas Sanders & Charles Stoecker
NBER Working Paper, September 2011
Abstract:
Fetal health is an important consideration in the formation of health-based policy. However, a complete census of true fetal deaths is impossible to obtain. We present the gender ratio of live births as an under-exploited metric of fetal health and apply it to examine the effects of air quality on fetal health. Males are more vulnerable to side effects of maternal stress in utero, and thus are more likely to suffer fetal death due to pollution exposure. We demonstrate this metric in the context of the Clean Air Act Amendments of 1970 (CAAA) which provide a source of exogenous variation in county-level ambient total suspended particulate matter (TSPs). We find that a standard deviation increase in annual average TSPs (approximately 35 μ g/m3) decreases the percentage of live births that are male by 3.1 percentage points. We then explore the use of observed differences in neonatal and one-year mortality rates across genders in response to pollution exposure as a metric to estimate total fetal losses in utero. These calculations suggest the pollution reductions from the CAAA prevented approximately 21,000-134,000 fetal deaths in 1972.
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Competitive Disadvantage Makes Attitudes Towards Rape Less Negative
Kevin Nunes & Cathrine Pettersen
Evolutionary Psychology, October 2011, Pages 509-521
Abstract:
Evolutionary theorists have argued that perceived competitive disadvantage may lead to more positive evaluation of, and greater likelihood of engaging in, risky and antisocial behavior. However, experimental studies have not yet examined the effects of competitive disadvantage on perceptions of rape. In the current study, we created a manipulation of perceived competitive status to test its effects on beliefs about rape. In one condition, participants were made to feel disadvantaged relative to male peers in terms of financial, physical, and intellectual power, whereas in the other condition they were made to feel advantaged. Participants were 120 heterosexual male undergraduate students. The manipulation was effective; compared to participants in the advantage condition, those in the disadvantage condition rated themselves as significantly worse off financially, shorter, in worse physical shape, and as having lower course marks than the average male student at the university. Compared to perceived competitive advantage, perceived disadvantage led to less negative attitudes towards rape. However, perceived competitive status did not significantly affect justifications and excuses for rape. Future studies using similar experimental manipulations can complement correlational studies and may contribute to greater clarity, precision, and sophistication of research and theory on the role of competitive disadvantage in rape.
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Kathrin Stanger-Hall & David Hall
PLoS ONE, October 2011, e24658
Abstract:
The United States ranks first among developed nations in rates of both teenage pregnancy and sexually transmitted diseases. In an effort to reduce these rates, the U.S. government has funded abstinence-only sex education programs for more than a decade. However, a public controversy remains over whether this investment has been successful and whether these programs should be continued. Using the most recent national data (2005) from all U.S. states with information on sex education laws or policies (N = 48), we show that increasing emphasis on abstinence education is positively correlated with teenage pregnancy and birth rates. This trend remains significant after accounting for socioeconomic status, teen educational attainment, ethnic composition of the teen population, and availability of Medicaid waivers for family planning services in each state. These data show clearly that abstinence-only education as a state policy is ineffective in preventing teenage pregnancy and may actually be contributing to the high teenage pregnancy rates in the U.S. In alignment with the new evidence-based Teen Pregnancy Prevention Initiative and the Precaution Adoption Process Model advocated by the National Institutes of Health, we propose the integration of comprehensive sex and STD education into the biology curriculum in middle and high school science classes and a parallel social studies curriculum that addresses risk-aversion behaviors and planning for the future.
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Ancient DNA suggests the leading role played by men in the Neolithic dissemination
Marie Lacan et al.
Proceedings of the National Academy of Sciences, 8 November 2011, Pages 18255-18259
Abstract:
The impact of the Neolithic dispersal on the western European populations is subject to continuing debate. To trace and date genetic lineages potentially brought during this transition and so understand the origin of the gene pool of current populations, we studied DNA extracted from human remains excavated in a Spanish funeral cave dating from the beginning of the fifth millennium B.C. Thanks to a "multimarkers" approach based on the analysis of mitochondrial and nuclear DNA (autosomes and Y-chromosome), we obtained information on the early Neolithic funeral practices and on the biogeographical origin of the inhumed individuals. No close kinship was detected. Maternal haplogroups found are consistent with pre-Neolithic settlement, whereas the Y-chromosomal analyses permitted confirmation of the existence in Spain approximately 7,000 y ago of two haplogroups previously associated with the Neolithic transition: G2a and E1b1b1a1b. These results are highly consistent with those previously found in Neolithic individuals from French Late Neolithic individuals, indicating a surprising temporal genetic homogeneity in these groups. The high frequency of G2a in Neolithic samples in western Europe could suggest, furthermore, that the role of men during Neolithic dispersal could be greater than currently estimated.