Male and female components of perinatal mortality: International trends, 1901–63

Analysis of vital data from five West European countries indicates that there has been a decline in the relative male risk and the sex ratio of late fetal mortality during the period 1901–1963. However, this decline is largely compensated for by an increase in the relative male risk and sex ratio of early neonatal mortality. As a result, no clear and consistent trend in the relative male risk or sex ratio of perinatal mortality can be detected. It is suggested that improvements in obstetric practice or in registration effectiveness may be responsible for the phenomena noted. Whatever the explanation, the findings illustrate the dangers of reifying registration definitions in the analysis of vital events.     

Sex mortality differences in The United States: The role of cohort smoking patterns

This article demonstrates that over the period 1948-2003, sex differences in mortality in the age range 50-84 widened and then narrowed on a cohort basis rather than on a period basis. The cohort with the maximum excess of male mortality was born shortly after the turn of the century. Three separate data sources suggest that the turnaround in sex mortality differences is consistent with sex differences in cigarette smoking by cohort. An age-period-cohort model reveals a highly significant effect of smoking histories on men's and women's mortality. Combined with recent changes in smoking patterns, the model suggests that sex differences in mortality will narrow dramatically in coming decades.     

Sex differences in mortality as a social indicator

Using a macro-sociological model, this paper argues that the status of women is an important determinant of sex mortality differences. This is done first by examining data from India which is known to have an excessively high level of female mortality. The examination is further extended by a pooled cross-section and time series analysis of the excess of female life expectancy over male life expectancy for 83 countries.     

Why Is Infant Mortality Higher in Boys Than in Girls? A New Hypothesis Based on Preconception Environment and Evidence From a Large Sample of Twins

Infant mortality is higher in boys than girls in most parts of the world. This has been explained by sex differences in genetic and biological makeup, with boys being biologically weaker and more susceptible to diseases and premature death. At the same time, recent studies have found that numerous preconception or prenatal environmental factors affect the probability of a baby being conceived male or female. I propose that these environmental factors also explain sex differences in mortality. I contribute a new methodology of distinguishing between child biology and preconception environment by comparing male-female differences in mortality across opposite-sex twins, same-sex twins, and all twins. Using a large sample of twins from sub-Saharan Africa, I find that both preconception environment and child biology increase the mortality of male infants, but the effect of biology is substantially smaller than the literature suggests. I also estimate the interacting effects of biology with some intrauterine and external environmental factors, including birth order within a twin pair, social status, and climate. I find that a twin is more likely to be male if he is the firstborn, born to an educated mother, or born in certain climatic conditions. Male firstborns are more likely to survive than female firstborns, but only during the neonatal period. Finally, mortality is not affected by the interactions between biology and climate or between biology and social status.     

Gender equality and the sex differential in mortality from accidents in high income nations

Despite their neglect by researchers relative to other causes of death, motor vehicle and other accidents contribute substantially to sex differences in mortality and address theoretical debates over the consequences of gender equality. A reduction-in-protection hypothesis argues that gender equality reduces the female advantage in accident mortality, a reduction-in-inequality hypothesis argues that gender equality increases the advantage, and an institutional adjustment hypothesis argues that gender equality initially reduces and then increases the advantage. The analysis tests these hypotheses using data on age-specific male and female accident mortality rates and indicators of work and family status for 18 high income nations from 1955–1994.In support of the institutional adjustment hypothesis, declining differentials in male and female motor vehicle and other accident mortality rates level off and sometimes increase in recent years, and measures of work and family change generally have similar curvilinear influences on the differential. Across nations, gender equality speeds the reversal in the differential for motor vehicle accidents, but not for other accidents.     

The 1918 Influenza Epidemic's Effects on Sex Differentials in Mortality in the United States

The 1918 influenza epidemic had a marked and fairly long‐lasting effect on the sex differential in mortality in the United States. After 1918 women lost most of their mortality advantage over men and the female/male gap did not regain its pre‐epidemic level until the 1930s. An analysis of causes of deaths shows a link with tuberculosis. We conjecture the existence of a selection effect, whereby many 1918 influenza deaths were among tuberculous persons, so that tuberculosis death rates dropped in later years, disproportionately among males. Age‐ and sex‐specific data by cause of death corroborate this hypothesis.     

Sex ratios in laboratory and field populations of the old field mouse,Peromyscus polionotus

Summary Males outnumbered females as juveniles but not as adults among mice captured by hand in their burrows. The higher production of male offspring together with their higher mortality rate resulted in a 1∶1 sex ratio for the adult mice. Despite the equal abundance of each sex, more males than females were caught in traps. Males must have a higher chance of encountering a trap and/or of entering a trap after finding it.     

Ten Thousand Tonga: A Longitudinal Anthropological Study from Southern Zambia, 1956–1991

The Gwembe Study was launched in 1956 to monitor the responses of 57,000 Tonga-speakers from the Middle Zambezi Valley to involuntary relocation. Since then, periodic censuses and frequent field visits have generated a wide variety of information. This article examines the demography of four Gwembe Tonga villages from 1956 to 1991, a period characterized first by relocation, then prosperity, and finally by economic hardship. White nuptiality does not respond significantly to socio-economic trends, marital fertility falls sharply during relocation, rebounds with the onset of prosperity, and decreases slowly during the most recent decade of economic hardship. Mortality of the very young and old is also sensitive to such changes. There is striking excess male mortality in all periods, especially among male infants and in particular male twins. The sex ratio at ‘birth’ is 92. This abnormal sex ratio at birth may be the result of conscious sex preference favouring females.     

Women in the driver's seat: Trends in sex differences in driving and death

The social meanings associated with the control of automobiles, involving among other things power, prestige, and independence, have led to driving being defined traditionally as within the masculine purview. One consequence of changing sex roles has been women's gradual usurpation of this formerly male prerogative. The proportion of women licensed to drive has increased markedly, a difference especially pronounced among the younger age groups. Male drivers log more miles than female drivers, and male accident rates have traditionally been higher than female rates. However, controlling for exposure to risk, the sex difference in accident rates has declined, and female mortality from traffic accidents has increased markedly. The possibility of sex differences in driving style is discussed. If driver-education programs and other attempts at intervention are to be effective, then it is important to become cognizant of women, especially young women, as a new population-at-risk, and to modify efforts so as to reach this new target group.Women in the Driver's Seat is part of a larger study of sex roles: Dying To Be Equal: Accelerating Trends in Female Mortality, coauthored with Ellen Gee, in preparation. A preliminary version was presented to the Society for the Study of Social Problems at their annual meeting in New York City, August, 1980.     

Social,behavioral, and biological factors,and sex differences in mortality

Few studies have examined whether sex differences in mortality are associated with different distributions of risk factors or result from the unique relationships between risk factors and mortality for men and women. We extend previous research by systematically testing a variety of factors, including health behaviors, social ties, socioeconomic status, and biological indicators of health. We employ the National Health and Nutritional Examination Survey III Linked Mortality File and use Cox proportional hazards models to examine sex differences in adult mortality in the United States. Our findings document that social and behavioral characteristics are key factors related to the sex gap in mortality. Once we control for women’s lower levels of marriage, poverty, and exercise, the sex gap in mortality widens; and once we control for women’s greater propensity to visit with friends and relatives, attend religious services, and abstain from smoking, the sex gap in mortality narrows. Biological factors—including indicators of inflammation and cardiovascular risk—also inform sex differences in mortality. Nevertheless, persistent sex differences in mortality remain: compared with women, men have 30% to 83% higher risks of death over the follow-up period, depending on the covariates included in the model. Although the prevalence ofriskfactors differs by sex, the impact of those riskfactors on mortality is similar for men and women.     

The narrowing sex differential in life expectancy in high-income populations: effects of differences in the age pattern of mortality

Using data from the Human Mortality Database for 29 high-income national populations (1751-2004), we review trends in the sex differential in e(0). The widening of this gap during most of the 1900s was due largely to a slower mortality decline for males than females, which previous studies attributed to behavioural factors (e.g., smoking). More recently, the gap began to narrow in most countries, and researchers tried to explain this reversal with the same factors. However, our decomposition analysis reveals that, for the majority of countries, the recent narrowing is due primarily to sex differences in the age pattern of mortality rather than declining sex ratios in mortality: the same rate of mortality decline produces smaller gains in e(0) for women than for men because women's deaths are less dispersed across age (i.e., survivorship is more rectangular).     

The role of smoking in the explanation of the Israeli Jewish pattern of sex differentials in mortality

The difference in life expectancy between women and men among Israeli Jews is very low relative to the difference in other developed countries, and the reasons for this are not fully understood. This paper explores the contribution of smoking to the observed patterns of sex-specific mortality among Israeli Jews, and to the sex difference in mortality exhibited by this population. The results show that the mortality of Israeli Jewish men is low owing to the relatively weak impact of smoking-related mortality, and that this also contributes to an explanation of the small sex difference. The result is explained by the high level of health-protective behaviour of Israeli Jewish men, including a low intensity of smoking (though not a low prevalence). The findings could have implications for some debates on the determinants of divergences and convergences in mortality, and research into the relationship between mortality and the Mediterranean diet.     

The dynamics of the population sex ratio in India, 1971-96

This paper reconstructs the trend in the population sex ratio in India between 1971 ad 1996 from available information on changes in sex differentials in mortality in the country since the beginning of the century. It is estimated that, although the mortality of females relative to that of males in India has improved since 1968, the population sex ratio increased between 1971 and 1981, stayed constant between 1981 and 1991, and started to decrease only after 1991. This implies that the recorded decrease and increase in the periods 1971-81 and 1981-91 respectively were both spurious and were the results of undercounts of females in 1971 and 1991. Another implication of this finding is that, owing to the lagged effect of past mortality on current trends in the population sex ratio, this ratio is a bad proxy for use in the study of changes in differential mortality by sex.     

The dynamics of the population sex ratio in India, 1971–96

This paper reconstructs the trend in the population sex ratio in India between 1971 and 1996 from available information on changes in sex differentials in mortality in the country since the beginning of the century. It is estimated that, although the mortality of females relative to that of males in India has improved since 1968, the population sex ratio increased between 1971 and 1981, stayed constant between 1981 and 1991, and started to decrease only after 1991. This implies that the recorded decrease and increase in the periods 1971–81 and 1981–91 respectively were both spurious and were the results of undercounts of females in 1971 and 1991. Another implication of this finding is that, owing to the lagged effect of past mortality on current trends in the population sex ratio, this ratio is a bad proxy for use in the study of changes in differential mortality by sex.     

性别失衡背景下大龄未婚男性的商业性行为——基于中国农村地区的研究发现

基于2008年安徽省CH市JC区的调查数据,通过与同年龄段已婚男性的对比,对性别失衡背景下中国农村大龄未婚男性的商业性行为、安全套使用情况及其影响因素进行分析。研究发现,在中国性别失衡背景下,男性婚姻挤压导致大龄未婚男性难以获取正常、稳定的性行为,商业性行为作为一种有效的替代和弥补方式,其发生率在农村地区的大龄未婚男性当中存在显著升高的可能性;相对于较高的商业性行为发生率而言,大龄未婚男性的安全套使用率处于较低的水平,使得大龄未婚男性的商业性行为具有高风险特征。     

The narrowing sex differential in life expectancy in high-income populations: Effects of differences in the age pattern of mortality

Using data from the Human Mortality Database for 29 high-income national populations (1751–2004), we review trends in the sex differential in e(0). The widening of this gap during most of the 1900s was due largely to a slower mortality decline for males than females, which previous studies attributed to behavioural factors (e.g., smoking). More recently, the gap began to narrow in most countries, and researchers tried to explain this reversal with the same factors. However, our decomposition analysis reveals that, for the majority of countries, the recent narrowing is due primarily to sex differences in the age pattern of mortality rather than declining sex ratios in mortality: the same rate of mortality decline produces smaller gains in e(0) for women than for men because women's deaths are less dispersed across age (i.e., survivorship is more rectangular).     

Incarcerating death: Mortality in U.S. state correctional facilities, 1985–1998

Using data from the U.S. Bureau of Justice Statistics and Census Bureau, I estimate death rates of working-age prisoners and nonprisoners by sex and race. Incarceration was more detrimental to females in comparison to their male counterparts in the period covered by this study. White male prisoners had higher death rates than white males who were not in prison. Black male prisoners, however, consistently exhibited lower death rates than black male nonprisoners did. Additionally, the findings indicate that while the relative difference in mortality levels of white and black males was quite high outside of prison, it essentially disappeared in prison. Notably, removing deaths caused by firearms and motor vehicles in the nonprison population accounted for some of the mortality differential between black prisoners and nonprisoners. The death rates of the other groups analyzed suggest that prison is an unhealthy environment; yet, prison appears to be a healthier place than the typical environment of the nonincarcerated black male population. These findings suggest that firearms and motor vehicle accidents do not sufficiently explain the higher death rates of black males, and they indicate that a lack of basic healthcare may be implicated in the death rates of black males not incarcerated.     

Some aspects of the relationship between the levels of infant mortality and fertility in the ESCAP region

The death of a child within the first year of life is a crucial factor in fertility decisions in a developing country. The infant mortality rate gives a close, inverse indication of the socioeconomic conditions of a country. This paper presents studies by Brass, Rutherford, Chowdhury, Khan and Chen, Agrawal, Iskander and Jones, in summary/abstract form. It concludes that the probabilities of survival are poorer for births of older women and/or higher parities. Early child deaths may increase the total period of exposure to the risk of conception. A lower infant and child mortality norm calls for fewer births to meet the needs for survivors. Child replacement motivational response seems to be strongest with the birth immediately following a death event. Agrawal analyzed the interval between successive births of 1107 women of Patna, Pakistan, according to the age of mother and sex and fate of the previous child. He observed that if a child died shortly after its birth, often a new pregnancy began within a short interval. The interval between 2 consecutive live births when the previous child was male and alive was greater than when the previous child was female and alive. The interval between 2 births was reduced if the child died in infancy and specially if this was a male child.     

甘南藏族自治州男性人口生命表和死亡分析

本文用Brass曾生子女存活比估算儿童死亡率的方法和Gompertz死亡率定律等方法对甘南藏族自治州的“五普”男性人口的死亡和生存原始数据作了进一步的修匀和校正。在此基础上。我们用Farlle死亡概率法编制出了甘南藏族自治州男性人口的简略生命表．并通过生命表的结果分析了甘南州男性人口的死亡水平、死亡模式和死亡的性别格局。