Mortality–fertility synergies during the demographic transition in the developed world

The classic theory used to explain the demographic transition assumes that mortality is the key explanatory variable influencing the decline in fertility. However, the empirical results obtained in what is known as the Princeton European Fertility Project have led many specialists to question this assumption. Using both national and provincial aggregated data for 25 countries over a long time span, the analysis reported in this paper found that mortality does indeed play a fundamental role in accounting for the main demographic changes that occurred both before and during the transitional period. Others’ research based on individual data has shown clearly that the number of surviving children was indeed an important factor for reproductive decisions. My analysis, using aggregated data, reached largely similar conclusions regarding the role of mortality in changing reproductive trends, via its impact on nuptiality and marital fertility at different stages of the demographic transition.     

Sex preference for children in German villages during the fertility transition

In the past, parents' sex preferences for their children have proved difficult to verify. This study used John Knodel's German village genealogies of couples married between 1815 and 1899 to investigate sex preferences for children during the fertility transition. Event history analyses of couples' propensity to progress to a fifth parity was used to test whether the probability of having additional children was influenced by the sex composition of surviving children. It appears that son preference influenced reproductive behaviour: couples having only girls experienced significantly higher transition rates than those having only boys or a mixed sibset. However, couples who married after about 1870 began to exhibit fertility behaviour consistent with the choice to have at least one surviving boy and girl. This result represents a surprisingly early move towards the symmetrical sex preference typical of modern European populations.     

Household access to capital and its effects on drought adaptation and migration: a case study of rural Alberta in the 1930s

This article reports findings from an empirical study of the impacts of drought on rural households in southeastern Alberta, Canada during the 1930s. In that decade, extreme summer heat conditions and low precipitation levels led to repeated crop failures. These extreme climatic conditions coincided with economic recession, falling commodity prices, and rising unemployment to create widespread hardship and suffering across the rural population. Thousands of households adapted by leaving the drought-stricken region and migrating to more northerly regions unaffected by drought, often suffering still further hardship as they reestablished themselves in a new environment. Through secondary research of historical documents and interviews with surviving migrants and non-migrants, this study identifies how economic, human, and social capital influenced the adaptive capacity, adaptation decisions, and migration behavior of rural households and describes how institutional responses affected household adaptation. Differential access to capital in its various forms was a key factor that distinguished households that adapted via migration from those that did not. The findings from this study of historical environment-related population change provide insights that enhance our broader understanding of potential future migration responses to the impacts of anthropogenic climate change and important considerations for policy-makers and planners seeking to build adaptive capacity in rural populations.     

Falling Short of Highest Life Expectancy: How Many Americans Might Have Been Alive in the Twentieth Century?

Life expectancy at birth in the United States during the twentieth century was lower than in many other highly developed countries. We investigate how this mortality disadvantage in the last 100 years translates into the number of hypothetical lives lost and their sex and age structure. We estimate the hypothetical US population if it had experienced in each decade since 1900 the mortality level of the country with the then highest life expectancy and compare the results to the actual figures in 2000. By 2000, the number of additional people who could have been alive had the mortality levels in the United States been as low as those in countries with the highest life expectancy was 66 million. This number is distributed equally between males and females. Suboptimal mortality at reproductive ages is crucial for the cumulative effect of potential lives lost, resulting from premature deaths of women who could still become first‐time mothers or bear additional children. Out of the 66 million additional persons who could have been alive in 2000, 45 million are attributable to those indirect deaths. Although the differences in the composition of the population by sex and age under the two mortality regimes are minor, the majority of people who might have been alive—54 million—were of working age or younger.     

Rethinking Historical Reproductive Change: Insights from Longitudinal Data for a Spanish Town

A set of linked reproductive histories taken from the Spanish town of Aranjuez between 1871 and 1950 is used to address key issues regarding reproductive change during the demographic transition. These include the role of child survival as a stimulus for reproductive change, the use of stopping and/or spacing strategies to achieve reproductive goals, and the timing of change. Straightforward demographic measures are used and robust results are achieved. Initial strategies of fertility limitation are shown to exist but are inefficient, are mostly visible during the latter part of the reproductive period, are designed mostly to protect families from the effects of increases in child survival, and are based almost entirely on stopping behavior. As mortality decline accelerates, strategies become much more efficient, are visible at the outset of married life, include spacing behavior, and eventually lead to important declines in completed family size. The results of this study have implications for our understanding of the demographic transition both in historical Europe and in other regions of the world.     

The Effects of Childhood,Adult, and Community Socioeconomic Conditions on Health and Mortality among Older Adults in China

Using a large, nationally representative longitudinal sample of Chinese aged 65 and older, this study examines the effects of childhood, adult, and community socioeconomic conditions on mortality and several major health outcomes. The role of social mobility is also tested. We find that childhood socioeconomic conditions exert long-term effects on functional limitations, cognitive impairment, self-rated health, and mortality independent of adult and community socioeconomic conditions. Achieved conditions matter for most outcomes as well, considering that adult and community socioeconomic conditions have additional impacts on health among Chinese elders. The majority of the effects of childhood conditions are not mediated by adult and community conditions. The results also show that social mobility and health in later life are linked in complex ways and that psychosocial factors have marginal explanatory power for the effects of socioeconomic conditions. Overall, this study provides new longitudinal evidence from China to support the notion that health and mortality at older ages are influenced by long-term and dynamic processes structured by the social stratification system. We discuss our findings in the context of the life course and ecological perspective, emphasizing that human development is influenced by a nexus of social experiences that impact individuals throughout life.     

Accounting for Cross-National Differences in Infant Mortality Decline (1965–1991) among less Developed Countries: Effects of Women's Status,Economic Dependency,and State Strength

The present study tests models derived from four theoretical perspectives: Modernization/free trade theory, gender inequality theory, developmental state theory, and dependency theory. It is based on a sample of 82 less developed countries for the period from 1965 to 1991. We find some support for each theoretical perspective. Foreign trade, investment, and debt dependency have adverse effects on infant mortality, mediated by variables linked to modernization/free trade theory and gender inequality theory. State strength has a beneficial direct effect on infant mortality decline. Women's education and reproductive autonomy have significant direct effects, but also play important roles as mediating variables as does rate of economic growth.     

New evidence about effects of reproductive variables on child mortality in sub-Saharan Africa

There is still considerable uncertainty about how reproductive factors affect child mortality. This study, based on Demographic and Health Survey data from 28 countries in sub-Saharan Africa, shows that mortality is highest for firstborn children with very young mothers. Other children with young mothers, or of high birth order, also experience high mortality. Net of maternal age and birth order, a short preceding birth interval is associated with above average mortality. These patterns change, however, if time-invariant unobserved mother-level characteristics of importance for both mortality and fertility are controlled for in a multilevel–multiprocess model. Most importantly, there are smaller advantages associated with longer birth intervals and being older at first birth. The implications of alternative reproductive ‘strategies’ are discussed, taking into account that if the mother is older at birth, the child will also be born in a later calendar year, when mortality may be lower.     

Theoretical consideration of effect of fishing mortality on growth and reproduction of fish populations

Summary An increase in fish mortality due to fishing can theoretically change the growth and reproduction of fish populations from the viewpoint of adaptation. We address the issue of how an iteroparous fish should convert surplus energy into somatic growth and reproduction at each age under given conditions of mortality. A model of life history, which maximizes the net reproductive rate using the discrete maximum principle, is improved employing a new relationship between body weight and surplus energy which we have recently proposed. The model is applied to the North Sea plaicePleuronectes platessa, for which it has been reported that the average length of young fish had increased whereas that of old ones had decreased for some decades. Although the model cannot directly explain the former phenomenon, the two phenomena can be interpreted as a change in the optimal life history due mainly to an increase in mortality.     

Reassessing the Insurance Effect: A Qualitative Analysis of Fertility Behavior in Senegal and Zimbabwe

A number of prominent demographers have recently reiterated the argument that a lasting mortality decline is a key determinant of the fertility transition. Of the main hypothesized pathways linking fertility to mortality, the one least studied is the insurance hypothesis: the notion that, in high‐mortality contexts, people decide to have more children in order to anticipate possible future child deaths and lessen the risks of having too few surviving offspring. In‐depth interviews and focus groups from Zimbabwe and Senegal are used to examine this hypothesis and to extend it into a broader theory of reproductive decision making under uncertainty. Whereas insurance strategies are frequent in Zimbabwe and occur in urban Senegal, in the higher‐mortality settings—the rural Senegalese site and the recent past described by respondents in Zimbabwe and urban Senegal—deliberate fertility‐limitation strategies are rare. The data depict fundamental changes in attitudes, strategies, and behaviors concerning family size over time and, in Senegal, over space. Important reproductive goals and risks extend far beyond numbers of children and mortality. Parents seek to have healthy, successful children for many reasons including companionship, descendants, and old‐age support. Diverse investments in child quality (their education, health, etc.) and quantity (numbers of births) are the main means to attain these goals and, less recognized by demographers, are also important ways for parents to manage uncertainty in family‐building outcomes; the “classic” insurance mechanism is only one, often minor, aspect of the quantity option.     

Parental age and offspring mortality: Negative effects of reproductive ageing may be counterbalanced by secular increases in longevity

As parental ages at birth continue to rise, concerns about the effects of fertility postponement on offspring are increasing. Due to reproductive ageing, advanced parental ages have been associated with negative health outcomes for offspring, including decreased longevity. The literature, however, has neglected to examine the potential benefits of being born at a later date. Secular declines in mortality mean that later birth cohorts are living longer. We analyse mortality over ages 30–74 among 1.9 million Swedish men and women born 1938–60, and use a sibling comparison design that accounts for all time-invariant factors shared by the siblings. When incorporating cohort improvements in mortality, we find that those born to older mothers do not suffer any significant mortality disadvantage, and that those born to older fathers have lower mortality. These findings are likely to be explained by secular declines in mortality counterbalancing the negative effects of reproductive ageing.     

Child Mortality in Beirut: Six Indirect Estimates Based on Data Collected at the Time of a Birth

Six indirect techniques for estimating child mortality were applied to information on survival status of all children ever born, provided by a sample of 1,252 women delivered at the Maternity Unit of the American University of Beirut Hospital. The results were compared, using as a reference the estimate derived from partial birth histories (ages of surviving children, ages at death of children who have died). Their dispersion is minimal for the probability of dying between birth and fifth birthday, estimated at 48 per thousand. For each mother, the ratio of the observed number of children who have died, to that expected given the lengths of exposure of the children to the risk of mortality, was used as a dependent variable in a multiple regression analysis. Educational level of mothers had a significant effect, but not occupational status of father, religion or consanguinuity.     

Spousal communication and contraceptive use among the Yoruba of Nigeria

A noted feature of many less developed societies is that marital partnershardly discuss reproductive issues with the result that decisions on theseissues are usually taken by men and their kinsmen. Because of lack ofspousal communication, negotiation for individual reproductive preferenceshas been limited. Thus, the reproductive preferences of men who desirelarger family sizes and oppose contraceptive use have usually been foundto prevail. The need to encourage husband-wife communication aboutreproductive issues cannot be overemphasized. The present study examinesthe level of spousal communication and its impact on contraceptive useamong Yoruba couples in southwest Nigeria. Data for the study are obtainedfrom a survey on the Role of Men in Family Planning conducted in one of thestates inhabited by the Yoruba of Nigeria – Ondo. The sample for this study consists of 381 monogamously married couples. Multivariate analyses were used to determine the impact of background variables on dependent variables. The study shows that fairly high percentages of men and women perceive that decisions on reproductive issues are taken jointly by both partners. The significantly high proportion of women who perceive that they participate in decision making is particularly worth noting and is an indication that women's voices are heard in the study society. Although the impact decreases on controlling for other variables, spousal communication was found to affect contraceptive use: contraceptive is higher among marital partners who discuss and take joint decisions on contraception. The study also reveals that family planning counseling has a significant impact on contraceptive use.     

Survival and sex composition of offspring: Individual-level responses in the quantum and tempo of childbearing during the demographic transition

Previous studies have documented varying fertility responses to childhood mortality and to the sex composition of the surviving offspring during the demographic transition. We contribute to this literature by applying a mixture cure model to reproductive histories of Estonian women born 1850–99. This model, unlike standard event history models, is capable of separating the effect of the covariates on the propensity of having another birth from their effect on its timing. Child fatalities, not having sons, and to a smaller extent, not having daughters, increased the propensity to have another child and decreased the interval to it. The response was stronger among later cohorts, but only with respect to parity progression. By contrast, the accelerated childbearing response diminished over time. Our findings suggest that behavioural responses in the quantum and tempo of childbearing can occur relatively independently.     

Effect of Conflict on Age at Marriage and Age at First Birth in Rwanda

Using Rwanda Demographic and Health Survey 2005 data, we estimate a Cox proportional hazard model to identify the determinants of age at marriage and age at first birth and whether these decisions were affected by conflict. We find that women living in clusters accounting for a larger proportion of sibling deaths in 1994, the year of the genocide, were more likely to marry later and have children later compared with those living in clusters accounting for a lower proportion of sibling deaths. Women living in regions with higher levels of under-five mortality were more likely to have their first child earlier compared with women living in regions with lower infant mortality. The age at marriage was probably affected by two reasons: the change in age structure and sex ratio of the population following the genocide, and the breakdown of kinship in the case of women who lost their siblings.     

Cigarette Smoking and All-Cause and Cause-Specific Adult Mortality in the United States

This study illuminates the association between cigarette smoking and adult mortality in the contemporary United States. Recent studies have estimated smoking-attributable mortality using indirect approaches or with sample data that are not nationally representative and that lack key confounders. We use the 1990–2011 National Health Interview Survey Linked Mortality Files to estimate relative risks of all-cause and cause-specific mortality for current and former smokers compared with never smokers. We examine causes of death established as attributable to smoking as well as additional causes that appear to be linked to smoking but have not yet been declared by the U.S. Surgeon General to be caused by smoking. Mortality risk is substantially elevated among smokers for established causes and moderately elevated for additional causes. We also decompose the mortality disadvantage among smokers by cause of death and estimate the number of smoking-attributable deaths for the U.S. adult population ages 35+, net of sociodemographic and behavioral confounders. The elevated risks translate to 481,887 excess deaths per year among current and former smokers compared with never smokers, 14 % to 15 % of which are due to the additional causes. The additional causes of death contribute to the health burden of smoking and should be considered in future studies of smoking-attributable mortality. This study demonstrates that smoking-attributable mortality must remain a top population health priority in the United States and makes several contributions to further underscore the human costs of this tragedy that has ravaged American society for more than a century.     

Men matter: Additive and interactive gendered preferences and reproductive behavior in kenya

The extent of men’s roles in reproductive decision-making in Africa is a subject of contention. Despite the volume of work on the roles men play in fertility decisions, there have been few attempts to derive direct empirical estimates of the effect of men’s preferences on reproductive behavior. I employ 1989 and 1993 Kenya Demographic and Health Surveys to examine the relative roles of the reproductive preferences of males and females on contraceptive use. Additive and interactive measures of preferences document a significant effect of men’s preferences, which may eclipse women’s preferences. The implications of these findings are discussed.     

The Consequences of Reproductive Failure: Dependence,Mobility, and Mortality among the Elderly of Rural South Asia

This paper examines the proposition that the economic mobility of persons in rural South Asia is affected by their reproductive outcomes: specifically, that reproductive failure (defined as the failure to rear a surviving son) entails material loss. Underlying this proposition is the notion that sons in this setting constitute an important source of insurance against the risk of income insufficiency in old age and in a variety of other contingencies. Analysis of data on living arrangements of the elderly in several rural South Asian communities and histories of asset gain and loss suggest that the consequences of reproductive failure include higher mortality risks and a high probability of property loss, that these consequences are more severe for women than for men, and are considerably more severe in rural Bangladesh than in the sampled areas of rural India.     

The increasing racial disparity in infant mortality: Respiratory distress syndrome and other causes

Although substantial declines in infant mortality rates have occurred across racial/ethnic groups, there has been a marked increase in relative black-white disparity in the risk of infant death over the past two decades. The objective of our analysis was to gain insight into the reasons for this growing inequality on the basis of data from linked cohort files for 1989-1990 and 1995-1998. We found a nationwide reversal from a survival advantage to a survival disadvantage for blacks with respect to respiratory distress syndrome over this period. The results are consistent with the view that the potential for a widening of the relative racial gap in infant mortality is high when innovations in health care occur in a continuing context of social inequality. As expected, the results for other causes of infant mortality, although similar, are less striking. Models of absolute change demonstrate that among low-weight births, absolute declines in mortality were greater for white infants than for black infants.     

Demographic transition theory

Demography is a science short on theory, rich in quantification. Nevertheless, demography has produced one of the best documented generalizations in the social sciences: the demographic transition. What is the demographic transition? Stripped to its essentials it is the theory that societies progress from a pre-modern regime of high fertility and high mortality to a post-modern regime of low fertility and low mortality. The cause of the transition has been sought in the reduction of the death rate by controlling epidemic and contagious diseases. Then, with modernization, children become more costly. Cultural changes weaken the importance of children. The increasing empowerment of women to make their own reproductive decisions leads to smaller families. Thus there is a change in values, emphasizing the quality of children rather than their quantity. In short, the fertility transition is becoming universal phenomenon, in which every country may be placed on a continuum of progress in the transition.