Revised regional model life tables at very low levels of mortality

This paper presents and discusses new model life tables at very low mortality, which make use of age-specific death rates from the 1960s, 1970s, and 1980s. These life tables fit recorded death rates in very low mortality populations better than do the existing ones at expectations of life of 77.5 and 80 years. The old tables incorporate too-high mortality at the higher ages and in infancy and they incorporate regional differences that no longer exist. The new tables "close out" the mortality schedules above age 80 more realistically. The convergence of age patterns of mortality at very high life expectancies in populations that used to conform to different families is in itself of demographic interest. Some convergence may perhaps be expected. Sullivan (1973) found that, in Taiwan, the comparison of mortality at ages 1-5 to mortality at 5-35 in the late 1950s showed higher mortality at the younger ages relative to the ensuing 30-year age interval than was found in any of the models, including the South model, which has the highest relative mortality from ages 1-5 among the 4 regional patterns. Then, in the late 1960s, the relation of mortality at 1-5 to mortality at 5-35 in Taiwan fell to a position intermediate between the West and South tables. Sullivan found in data on mortality by cause of death a large reduction in mortality from diarrhea and enteritis, no doubt as a result of environmental sanitation. Mortality from these causes is concentrated among young children, and reduction in deaths from these causes would naturally diminish the excess mortality in this age interval. The East pattern, characterized by very high mortality in infancy (but not from 1-5), may be the result of the prevalence of early weaning or avoidance of breast feeding altogether in the populations characterized by this pattern. As health conditions have improved, evidenced by the overall design of mortality, these special factors are diminished or erased. Model life tables at these very low mortality levels have different uses from most applications of model life tables at higher mortality. The use of model tables to estimate accurate schedules of mortality when the basic data are incomplete or inaccurate is less relevant in this range of mortality levels.     

Far eastern patterns of Mortality

Summary In this paper a mortality pattern is identified which has not previously been described by model mortality schedules and seems to have occurred only in populations in the Far East. Mortality schedules in Taiwan, Hong Kong, Singapore, and Korea during the past several decades have been characterized by excessively high death rates of men at the older ages. This excess mortality has progressively diminished and most recent death rates for men show only slight deviations from West model life tables. An examination of statistics on causes of death suggests that tuberculosis is at least partly responsible for the excess mortality of men.     

An evaluation of brass mortality estimates under conditions of declining mortality

An evaluation of the Brass childhood mortality estimates under conditions of declining mortality shows them to overestimate current mortality. Error increases as the rate of mortality decline increases, as the childhood age up to which cumulative mortality is being estimated increases, and as age at onset of childbearing decreases. We use the results to develop a method for correcting the Brass estimates for the effects of quasistability. The method requires an estimate of the rate of mortality decline within the population in addition to information on the pattern of childbearing in the population.     

Age patterns of mortality for older women: an analysis using the age-specific rate of mortality change with age

"In this paper we propose a mortality measure that seems useful in analyzing age patterns of death rates. The measure, which will be denoted by k(x), indicates the proportional increase or decrease with age in the risk of death at a given age x, and is called the age-specific rate of mortality change with age." Estimations are presented for women in 10 countries. "Eight of the selected sets of data are for developed nations in the 1960s and 1970s, and the other two sets of data, for Taiwan, 1931-35, and for Germany, 1910-11, represent relatively high mortality. For France and West Germany, three different periods are included for an investigation of cohort effects on the observed age patterns." Other mathematical models of age-specific mortality rates are discussed and compared. (SUMMARY IN FRE)     

Effect of mortality change on stable population parameters

The stable population model is used to establish formulas expressing the effects of mortality change on population growth rates, birth rates, and age composition. The change in the intrinsic growth rate is shown to be quite accurately approximated by the average decline in age-specific death rates between age zero and the mean age at childbearing in the stable population. This change is essentially independent of the initial level of fertility in the population. Changes in birth rates and age composition are shown to be simple functions of the age pattern of cumulative changes in mortality rates relative to an appropriately defined “neutral” standard.     

Socio-economic Differentials in Infant and Child Mortality during Mortality Decline: England and Wales, 1890–1911

In this paper data from the 1911 Census of the Fertility of Marriage of England and Wales are used to study patterns of mortality decline by socio-economic characteristics, principally the occupation of husband. That census reported data on number of wives, children ever born, and children dead by marriage-duration cohorts for 190 non-overlapping occupations of husband. These results, along with those on number of rooms in the dwelling of the family are used to make indirect estimates of childhood mortality using the techniques described in United Nations, Manual X. These procedures produce values of q(a), the probability of dying before reaching some exact age ‘a’. Estimates for q(2), q(3), q(5), q(10), q(15), and q(20) are derived from data on women married 0–4, 5–9, 10–14, 15–19, 20–24, and 25–29 years, respectively. These estimates can also be dated to a point in the past. These values can also be converted to a corresponding level of a Model West life table, which describes the ‘average’ mortality regime which the children of those women experienced. This furnishes a basis to look at mortality decline for various social classes and occupational groups. Ordinary least squares regressions of the levels of Model West life tables implied by the 1(a) values on time give one measure of mortality decline. Another is the absolute amount of the increase in the level of the Model West life tables from marriage-duration cohort 20–24 years to 0–4 years. The aggregate results indicate that social class in England and Wales during the 1890s and 1900s tended to be related to the speed of mortality decline: childhood mortality declined more rapidly in the higher and more privileged social class groups. But the results were neither nearly as strong nor as regular as those which predicted the level of mortality within any marriage-duration cohort. These outcomes are not particularly sensitive to the three different social-class stratification schemes used: the 1911 English Registrar General's classification; the 1951 English Registrar General's classification; and the 1950 U.S. Census classification. There was also a fairly regular and predictable gradient for the number of rooms in the home: child mortality was higher in families who lived in larger dwellings. Analysis of 190 detailed male occupational groups revealed that considerably more of the variation in mortality levels than of trends could be explained by social-class categories. Between 20 and 40 per cent of variation in mortality trend could be accounted for by social class alone, as opposed to 50 to 80 per cent of mortality levels for different marriage-duration cohorts. Results for a more restricted sample of 116 occupations for which income estimates could be made revealed a similar pattern. In addition, income was virtually unrelated to the pattern of mortality decline, and improvement was more rapid in groups who were more urban. This reflects the role of rapidly improving urban sanitation in the late nineteenth and early twentieth centuries in England. In contrast, income was significantly related to childhood morality levels for various marriage-duration cohorts (with higher income associated with lower mortality), while urbanization was inversely correlated with mortality levels (more urban groups experienced higher mortality). Overall, social class (or occupation group), income, and urbanization were more successful in explaining mortality levels than time trends across occupations, although social class and the extent of urbanization did reasonably well in accounting for trends. Over a longer period, the transition in child mortality was under way by the 1890s, but its pace and timing varied in different occupations and social class groupings. Although absolute differences in infant mortality were reduced after about 1911, relative inequality persisted even as infant and child survival improved for all groups.     

Infant mortality trends in rural East Pakistan

Infant mortality trends in a rural area of East Pakistan are analyzed utilizing the Bogue pregnancy history technique. The findings indicate that infant mortality has declined slightly over 20 percent between 1958 and 1967. The existence of development programs in women’s education and family planning since 1961 are proposed as possible reasons for this finding. A convergence in infant mortality rates to mothers in the age range 15–39 years was found in the final year under analysis, while the standard U shaped pattern of infant mortality with age structure was exhibited in the previous years. One possible explanation for the convergence is that the development programs are reaching women within this age range more equally than in the past. An alternative explanation relating to the problems of recall of mortality events was discussed.     

Some aspects of socio-economic determinants of mortality in tropical Africa

Measurements of mortality levels and trends continue to be inadequate in Africa, largely because of the lack of reliable and adequate information on deaths. A series of estimates depicting mortality levels and trends has been prepared by demographers, different kinds of data and employing different estimation procedures, but knowledge of the "true" structure of mortality in tropical Africa is virtually nonexistent. Because of these problems only a "bird's eye view" of the prevailing situation in tropical Africa is presented. The discussion -- directed to mortality by sex and age, by residence, and by cause -- is based on secondary and fragmentary data. Socioeconomic and cultural determinants of mortality are also examined. Available information on male and female mortality indicates that the death rates for males are higher than they are for females. Early childhood mortality (1-4 years) in tropical Africa is relatively high compared with the other age groups, including infants. Mortality differentials have been noted among geographical and administrative units and subdivisions of populations within the various countries of tropical Africa. Also, urban dwellers enjoy a higher expectation of life at birth than do rural dwellers. Communicable diseases are the main killers in tropical Africa. Persistent poverty and malnutrition, poor housing, unhealthy conditions in the growing cities, nonexistence of health facilities in the rural areas, rapid population expansion, and low levels of education are among the factors impeding progress in reducing mortality in tropical Africa. The need exists to express development goals in terms of the progressive reduction and eventual elimination of malnutrition, disease, illiteracy, squalor, and inequalities. Future trends in mortality in tropical Africa may depend more than they have in the recent past on economic and social development.     

Discrete Barker Frailty and Warped Mortality Dynamics at Older Ages

We develop a discrete variant of a general model for adult mortality influenced by the delayed impact of early conditions on adult health and mortality. The discrete variant of the model builds on an intuitively appealing interpretation of conditions that induce delayed effects and is an extension of the discrete form of the standard frailty model with distinct implications. We show that introducing delayed effects is equivalent to perturbing adult mortality patterns with a particular class of time-/age-varying frailty. We emphasize two main results. First, populations with delayed effects could experience unchanging or increasing adult mortality even when background mortality has been declining for long periods of time. Although this phenomenon also occurs in a regime with standard frailty, the distortions can be more severe under a regime with Barker frailty. As a consequence, conventional interpretations of the observed rates of adult mortality decline in societies that experience Barker frailty may be inappropriate. Second, the observed rate of senescence (slope of adult mortality rates) in populations with delayed effects could increase, decrease, or remain steady over time and across adult ages even though the rate of senescence of the background age pattern of mortality is time- and age-invariant. This second result implies that standard interpretations of empirical estimates of the slope of adult mortality rates in populations with delayed effects may be misleading because they can reflect mechanisms other than those inducing senescence as conventionally understood in the literature.     

Estimating infant and childhood mortality under conditions of changing mortality

Summary It is well known that estimates of infant mortality obtained using Brass's technique are very accurate. Biases are introduced, however, when one or more of the assumptions on which it relies are violated. Departures from the assumption of constant fertility may be handled by using a variant of the technique which depends on information on the age distribution of surviving children, rather than on indexes of the fertility function. Violations of the assumption of constant mortality - an increasingly common situation in most developing societies - produce upward biases in the estimates. The amount of bias is a function of the speed of mortality decline, the characteristics of the fertility pattern and, finally, of the age of the mother. This paper presents a simple technique which corrects these biases, and in addition, generates estimates of the parameters of the mortality trend. It differs from others in that it uses a cohort definition of mortality decline and relies on knowledge of the age structure of surviving children rather than on indexes of the fertility pattern.     

The impact of childhood mortality on Fertility in six rural Thanas of Bangladesh

In this article, we examine the relationship between child mortality and subsequent fertility using prospective longitudinal data on births and childhood deaths occurring to nearly 8000 Bangladeshi mothers observed over the 1982-1993 period, a time of rapid fertility decline. Generalized hazard-regression analyses are employed to assess the effect of infant and child mortality on the hazard of conception, with controls for birth order and maternal age and educational attainment. Results show that childhood mortality reduces the time to subsequent conception if the death occurs within a given interval, representing the combined effect of biological and volitional replacement. The time to conception is also reduced if a childhood death occurs during a prior birth interval, a finding that signifies an effect of volitional replacement of the child that died. Moreover, mortality effects in prior birth intervals are consistent with hypothesized insurance (or hoarding) effects. Interaction of replacement with elapsed time suggests that the volitional impact of child mortality increases as the demographic transition progresses. This volitional effect interacts with sex of index child. Investigation of higher-order interactions suggests that this gender-replacement effect has not changed over time.     

Mortality in Ghana: Evidence from the cape coast project data

This paper deals with the estimation of mortality for a rural community of about 20,000 persons in the rain-forest area of south-west Ghana. Specifically, infant, child and adult mortality estimates have been obtained by the application of a wide range of direct and indirect methods of measuring mortality from the different statistics collected by a longitudinal mortality and fertility project conducted during 1974–7. It was noted that infant and childhood mortality rates obtained from death registrations were consistent with those rates yielded by pregnancy histories and child survival statistics. However, the adult mortality estimates derived from orphanhood statistics tended to be lower than those suggested by death registrations. The analysis revealed an infant mortality rate of 100 for boys and 84 for girls, equal childhood mortality rates for boys and girls (85–6), a lower expectation of life at birth for men (45.8 years) than for women (52.8), and a much more severe incidence of mortality among men aged over 40 than for women at the corresponding ages.     

The Middle East population puzzle

An overview is provided of Middle Eastern countries on the following topics; population change, epidemiological transition theory and 4 patterns of transition in the middle East, transition in causes of death, infant mortality declines, war mortality, fertility, family planning, age and sex composition, ethnicity, educational status, urbanization, labor force, international labor migration, refugees, Jewish immigration, families, marriage patterns, and future growth. The Middle East is geographically defined as Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, Yemen, Gaza and the West Bank, Iran, Turkey, and Israel. The Middle East's population grew very little until 1990 when the population was 43 million. Population was about doubled in the mid-1950s at 80 million. Rapid growth occurred after 1950 with declines in mortality due to widespread disease control and sanitation efforts. Countries are grouped in the following ways: persistent high fertility and declining mortality with low to medium socioeconomic conditions (Jordan, Oman, Syria, Yemen, and the West Bank and Gaza), declining fertility and mortality in intermediate socioeconomic development (Egypt, Lebanon, Turkey, and Iran), high fertility and declining mortality in high socioeconomic conditions (Bahrain, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates), and low fertility and mortality in average socioeconomic conditions (Israel). As birth and death rates decline, there is an accompanying shift from communicable diseases to degenerative diseases and increases in life expectancy; this pattern is reflected in the available data from Egypt, Kuwait, and Israel. High infant and child mortality tends to remain a problem throughout the Middle East, with the exception of Israel and the Gulf States. War casualties are undetermined, yet have not impeded the fastest growing population growth rate in the world. The average fertility is 5 births/woman by the age of 45. Muslim countries tend to have larger families. Contraceptive use is low in the region, with the exception of Turkey and Egypt and among urban and educated populations. More than 40% of the population is under 15 years of age. The region is about 50% Arabic (140 million). Educational status has increased, particularly for men; the lowest literacy rates for women are in Yemen and Egypt. The largest countries are Iran, Turkey, and Egypt.     

Effects of early-life conditions on adult mortality: a review

"This paper considers the effects of health conditions in childhood on an individual's mortality risks as an adult. It examines epidemiologic evidence on some of the major mechanisms expected to create a linkage between childhood and adult mortality and reviews demographic and epidemiologic studies for evidence of the hypothesized linkages....Many empirical studies support the notion that childhood conditions play a major role in adult mortality, but only in the case of respiratory tuberculosis has the demographic importance of a specific mechanism been established by cohort studies. One's date and place of birth also appear to be persistently associated with risks of adult death in a wide variety of circumstances. An individual's height, perhaps the single best indicator of nutritional and disease environment in childhood, has recently been linked to adult mortality, especially from cardiovascular diseases. Further research is needed, however, before causal mechanisms can be identified."     

On the Far Eastern pattern of mortality

Since the early 1980s, it has been accepted widely that there is a Far Eastern pattern of mortality, a pattern characterized by excessively high death rates among older men relative to death rates among younger men and among women. It has been regarded as a unique regional mortality pattern, applying primarily to Far Eastern populations. A re-examination of the mortality data of some Far Eastern populations reveals that changes in both age patterns of and sex differentials in mortality have been widely observed. Further, mortality patterns similar to the so-called Far Eastern mortality model have been found in many other populations.     

On the Far Eastern pattern of mortality

Since the early 1980s, it has been accepted widely that there is a Far Eastern pattern of mortality, a pattern characterized by excessively high death rates among older men relative to death rates among younger men and among women. It has been regarded as a unique regional mortality pattern, applying primarily to Far Eastern populations. A re-examination of the mortality data of some Far Eastern populations reveals that changes in both age patterns of and sex differentials in mortality have been widely observed. Further, mortality patterns similar to the so-called Far Eastern mortality model have been found in many other populations.     

Early-life conditions and adult mortality decline in Dutch cohorts born 1812–1921

Mounting evidence suggests that early-life conditions have an enduring effect on an individual’s mortality risks as an adult. The contribution of improvements in early-life conditions to the overall decline in adult mortality, however, remains a debated issue. We provide an estimate of the contribution of improvements in early-life conditions to mortality decline after age 30 in Dutch cohorts born between 1812 and 1921. We used two proxies for early-life conditions: median height and early-childhood mortality. We estimate that improvements in early-life conditions contributed more than five years or about a third to the rise in women’s life expectancy at age 30. Improvements in early-life conditions contributed almost three years or more than a quarter to the rise in men’s life expectancy at age 30. Height appears to be the more important of the two proxies for early-life conditions.     

Evaluation of estimates of underenumeration in the census and the age pattern of mortality,philadelphia, 1880

The schedule of mortality by age for Philadelphia's 1880 population classified by sex and race showed aberrations from Coale and Demeny West, South, and North model life tables. Deviations from standard age patterns of mortality were especially pronounced for the black population. The question addressed in this paper is whether the alternative age patterns of mortality are produced by underenumeration in the 1880 census or by actual variations in the age-specific mortality experience. The conclusion was reached that the underenumeration of the urban population, especially the blacks, exceeds estimates for the national population. In addition, the results indicated that the black population faced risks of dying that genuinely differed from standard age patterns. An attempt to use a Brass logit model to generalize the black mortality experience met with success for females but not for males.     

A look at Asia's changing youth population

This report summarizes findings from a recent East-West Center study on demographic and social changes among young people aged 15-24 years in 17 countries in East, Southeast, and South Asia. Nearly every country in Asia has experienced fertility decline. Decline began in Japan and Singapore during the 1950s, followed by declines in Hong Kong, South Korea, Sri Lanka, the Philippines, Brunei, Taiwan, Malaysia, Thailand, and China during the 1960s. Declines occurred during the 1970s in Indonesia, India, and Myanmar. A "youth bulge" occurred about 20 years later due to declines in infant and child mortality. This bulge varies by country with the timing and magnitude of population growth and subsequent fertility decline. The proportion of youth population rises from 16% to 18% about 20 years after the beginning of fertility decline and declines to a much lower stable level after several decades. The bulge is large in countries with rapid fertility decline, such as China. Governments can minimize the effects of bulge on population growth by raising the legal age at marriage, lengthening the interval between first marriage and first birth, and increasing birth intervals. School enrollments among adolescents are rising. In South Korea, the population aged 15-24 years increased from 3.8 to 8.8 million during 1950-90, a rise of 132% compared to a rise of 653% among school enrollments. It is expected that the number of out-of-school youths will decline from 5.1 to 3.6 million during 1990-2025. Youth employment varies by gender. Policies/programs in family planning and reproductive health will need to address the changing needs of youth population.     

Mortality in Ghana: Evidence from the cape coast project data

Abstract This paper deals with the estimation of mortality for a rural community of about 20,000 persons in the rain-forest area of south-west Ghana. Specifically, infant, child and adult mortality estimates have been obtained by the application of a wide range of direct and indirect methods of measuring mortality from the different statistics collected by a longitudinal mortality and fertility project conducted during 1974-7. It was noted that infant and childhood mortality rates obtained from death registrations were consistent with those rates yielded by pregnancy histories and child survival statistics. However, the adult mortality estimates derived from orphanhood statistics tended to be lower than those suggested by death registrations. The analysis revealed an infant mortality rate of 100 for boys and 84 for girls, equal childhood mortality rates for boys and girls (85-6), a lower expectation of life at birth for men (45.8 years) than for women (52.8), and a much more severe incidence of mortality among men aged over 40 than for women at the corresponding ages.