Age patterns of mortality and cause-of-death structures in Sweden,Japan, and the United States

This paper uses a new standard model of adult mortality to compare the mortality patterns of Swedes, Japanese, and U.S. whites between 1950 and 1985. It examines changes in the age patterns of mortality and the cause-of-death structures within the populations. and the relationships between those two factors. As Japan has reached a level of mortality similar to that in Sweden, the age patterns of mortality in the two populations have become more similar despite distinct differences in causes of death. The United States has a cause-of-death structure similar to that of Sweden, but the age pattern of mortality is very different. High mortality in the middle age range in the United States results in approximately a one-year loss of life expectancy at age 45 in comparison with Sweden.     

Educational attainment and the (growing) importance of age structure: Indigenous and non-indigenous Australians

Australia’s Indigenous population has a markedly younger age structure than its non-Indigenous counterpart. As a result, greater proportions of the Indigenous population are presently at school and approaching tertiary education age, meaning that any declines in gaps between the two populations in terms of educational attainment may be more apparent than real; a reflection of the differing age structures, rather than true improvement. This paper illustrates the argument across the period 1981–2006. It shows first that crude gaps in educational attainment between the two populations in fact increased across the period, for both pre-tertiary (Year 12) attendance and post-school qualifications, after first declining slightly between 1981 and 1991. Using a classic standardization technique it then illustrates how the differences in age structure conceal what would otherwise be greater or smaller gaps. Although most of the age effects are at present small, the findings indicate the increasing optimality of the Indigenous age structure for the gaining of qualifications, and make it imperative that these differences be explicitly acknowledged and built into all policy interventions. Similarly the findings indicate that any such interventions should be carefully monitored for their potential to negatively discriminate on the basis of age structure.     

General growth balance method: A reformulation for populations open to migration

This paper proposes a reformulation of the general growth balance method for estimating census and registration completeness so as to make it applicable even to populations that are affected by migration. It also discusses a new procedure of line fitting that could be useful in countries where the input data are severely affected by age misreporting. The method is applicable to countries where data on age distribution of the population are available for two points in time from either censuses or surveys. Following closely the original proposal of Brass, it involves adjusting the 'partial' birth rates for age-specific disturbances from growth and migration rates. Beyond correcting the death rates, the method is useful in inferring the relative completeness of the censuses, and in deriving a robust estimate of birth rate under certain conditions. The application of the method is illustrated using the example of the male population of the Indian state of Uttar Pradesh for the period 1981 to 1991.     

General growth balance method: A reformulation for populations open to migration

This paper proposes a reformulation of the general growth balance method for estimating census and registration completeness so as to make it applicable even to populations that are affected by migration. It also discusses a new procedure of line fitting that could be useful in countries where the input data are severely affected by age misreporting. The method is applicable to countries where data on age distribution of the population are available for two points in time from either censuses or surveys. Following closely the original proposal of Brass, it involves adjusting the ‘partial’ birth rates for age-specific disturbances from growth and migration rates. Beyond correcting the death rates, the method is useful in inferring the relative completeness of the censuses, and in deriving a robust estimate of birth rate under certain conditions. The application of the method is illustrated using the example of the male population of the Indian state of Uttar Pradesh for the period 1981 to 1991.     

The longevity of Jews in Canada, 1940–1942

A life table for the Jewish population of Canada, based upon their mortality experience during 1940–2, yielded an average length of life (expectation of life at birth) of 67–53 years for males and 69·89 years for females. These figures are greater than those for the general population of Canada by 4·58 years for males and 3·60 years for females. These margins decrease with advance in age; the expectations of life for Jews and for the total Canadian population are equal at age 25 in the case of females, and at age 35 in the case of males.

Jewish infants in Canada start life with a mortality rate, in the first year, only two-fifths of that for the general population. This advantage for Jews is observed through childhood, adolescence, and early maturity. However, the margin between the Jewish and total populations decreased with advance in age until, shortly after age 50, the Jews begin to show the higher mortality rates.

The Jewish populations of the United States and of Canada have great similarities in their social and economic structures. They also share, very largely, in their European origins, and they have come to North America during the same period. It is, therefore, a fair assumption that the longevity and mortality characteristics of the relatively small Jewish population of Canada may be indicative of what might be found for the millions of Jews in the United States, for whom such information is not available.     

The data and the dynamics of the Chinese populations

Historical demographic data on populations of the Chinese cultural area including counts, registrations, and continuous records are discussed in terms of problems of analysis. For many decades, censuses, investigations, and registration reports yielded generally faulty data on the numbers, and the age and sex structures of the populations. The problem here is not the adjustment of age and sex structures, but the use of faulty structures to estimate the dynamics of the population in the absence of either successive investigations or vital statistics. This paper analyzes these problems according to historical eras (Chinese Farm Population 1919-1932) or geographical areas (Taiwan, Manchuria, etc.). The writer concludes that further pursuit of estimates that agree with the Chinese demographic realities of the period requires a) a wider integration of comparable data and b) adjustment of age structures in relation to the habitual errors in response, the systematic biases in registration, and the deviations reflecting erratic factors or historic events.     

Relation between exploitation and production in experimental populations ofPoecilia reticulata

Summary In order to make researches on the effect of exploitation upon fish populations, six populations of guppy were maintained during a period of 331 weeks under conditions of space, light, temperature, pH, and food controlled as much as possible. The six populations were divided into three groups two by two: a control group without exploitation, a 10% rate of exploitation group and a 20 and 33% rate of exploitation group. All the populations repeated an increase and a decrease in number and in biomass about once a year. The exploitation affected the age composition in the populations: in the non-exploited population adults occupied the largest part, and the more intensive the exploitation the larger the part fry occupied. The exploitation decreased the biomass of exploited populations, but productivity increased with increasing of of rate of exploitation. The relationship between adult and fry could be represented byRicker's reproduction curve. The form of the curve was changed by an intensity of exploitation. It was thought that exploitation acts as a preventer of aging of populations by removing old fish and results increasing number of fry and productivity.     

Structure and change in causes of death: An international summary

Abstract Model patterns of the cause structure of mortality at different levels were established for males and females, based on data for 165 national populations. These patterns suggest that the cause of death most responsible for mortality variation is influenza/bronchitis, followed by 'other infectious and parasitic diseases', respiratory tuberculosis, and diarrhoeal disease. Together, these causes typically account for about 60 per cent of the change in level of mortality from all causes combined. Their respective contributions have not depended in an important way on the initial level of mortality. These results - especially tbe importance of the respiratory and diarrhoeal diseases - imply that past accounts may have over-emphasized the role in mortality decline of specific and well-defined infectious diseases and their corresponding methods of control. There is strong statistical support for the suggestion that most of the remainder of mortality variation should be ascribed to changes in cardio-vascular diseases, but that methods of cause-of-death assignment in high-mortality populations have often obscured the importance of these diseases. When death rates from 'other and unknown' causes are held constant, changes in cardio-vascular disease account for about one-quarter of the decline in mortality from 'all causes'.Although the causal factors are poorly established, corroborative results have been demonstrated cross-sectionally in the United States. The composition of the group of populations most deviant from the structural norms is apparently dominated by differentials in the mode of assigning deaths to cardio-vascular disease. However, when broad groups of regions or periods are distinguished, more subtle differences emerge. Controlling mortality level for all causes combined, diarrhoeal diseases are significantly higher in non-Western populations and southern/eastern Europe than in overseas Europe or northern/western Europe. These differences are probably related to standards of nutrition and personal hygiene, but may also reflect climatic factors. Much higher cardio-vascular mortality in overseas European populations than in non-Western populations at similar overall levels probably reflects variation in habits of life. Regional differences in death rates from violence, maternal mortality, respiratory tuberculosis and influenza/pneumonia/bronchitis are briefly noted and commented upon. Cause-of-death structures at a particular level of mortality display some important changes over time. Respiratory tuberculosis and 'other infectious and parasitic diseases' have tended to contribute less and less to a certain level of mortality. They have in part been 'replaced' by diarrhoeal disease, specifically in non-Western populations. These developments reflect an accelerating rate of medical and public health progress against the specific infectious diseases, and a disappointing rate of progress against diarrhoeal disease. Western and non-western populations have shared to approximately the same extent in the accelerating progress against infectious diseases, and developments during the post-war period are more appropriately viewed as an extension of prior trends rather than as radical departures therefrom. For males, cardio-vascular disease and cancer have significantly increased their contribution to a particular level of mortality, while no such tendency is apparent for females. These developments may be related to changes in personal behaviour and in environmental influences whose differential impact on the sexes has been demonstrated in epidemiological studies. Although we have avoided an explicit treatment of age by having recourse at the outset to standardization, certain of the results are apparently reflected in studies of age patterns of mortality. The joint occurrence in non-Western populations and Southern/Eastern populations of exceptionally high death rates from diarrhoeal disease may explain why the 'South' age-pattern, with it high death rates between ages one and five, is often the most accurate referent for use in Latin America and Asia. The fact that the list of populations with the least deviation cause structure is almost exclusively confined to members of the 'West' group of Coale and Demeny may account for the lack of persistent deviation in this group's age patterns. Finally, tbe increasing importance of cardio-vascular disease and neoplasms in cause-of-death structures for males but not females is probably associated with the changing age patterns of male mortality noted by Coale and Demeny.     

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.     

百万以上少数民族老龄化程度的分层测算

老龄化是当今面临的一大社会问题。通常老龄化的界定主要采用老年人口占比这一指标来量化。以发展的视角与人口年龄结构划分标准而言．单一指标的老龄化论断削弱了学术的严谨性和对现实的指导性。为精确各个族群老龄化的差异,以发展的视角分析出台减缓老龄化进程的相关策略．使区域经济发展与老龄化进程趋向协调．本文基于第四、五、六次人口普查数据资料．对百万以上18个少数民族的老龄化程度进行新的分层测算。在分析其老龄化现状的基础上。给出1990年、2000年、2010年三个时段的年龄结构类型．分层测算了18个民族20年间年龄结构类型或老龄化进程的速度和差异．为国家制定分层策略提供数据化支撑,     

A New Method for Determining Why Length of Life is More Unequal in Some Populations Than in Others

Why is there greater variability in individual longevity in some populations than in others? We propose a decomposition method designed to address that question by quantifying the effects of population differences in the spread, allocation, and timing of the principal causes of death. Applying the method to the United States and Sweden, we find that spread effects account for about two-thirds of the greater variance in age at death among American adults, meaning that two-thirds of the U.S.-Sweden difference would persist if the two countries differed only with respect to within-cause variance among adults. The remainder of the difference is due largely to allocation effects, with the greater incidence of homicides and fatal traffic accidents alone accounting for more than one-fourth of the greater variance in age at death among adults in the United States.     

Vitality and malaise in demography: outlook and strategies for the future

"When dealing with age structures...the question could be posed...whether in the age structure such pronounced 'distortions' already exist as to make a major contribution to plotting the course of demography and then, as a more or less inevitable consequence, to shaping the social and economic context. In other words, whether conditions of 'demographic malaise' exist linked, on the one hand, to an extraordinarily young age structure and a consequent 'excess' population growth...and, on the other, to an extraordinarily old age structure and a subsequent 'excess' population decline.... This study proposes to focus particularly on this second instance, which pertains to contemporary western populations or sub-populations, [using the example of Italy]."     

A Comparative Evaluation of Error and Bias in Census Tract-Level Age/Sex-Specific Population Estimates: Component I (Net-Migration) vs Component III (Hamilton–Perry)

While the housing-unit method continues to be the preferred method nationwide for producing small-area population estimates, this procedures lacks a method for making age/sex-specific estimates. This paper reports evaluation research on implementation of component-based methods for estimating census tract populations with age/sex detail. Two alternatives are explored: (1) the Component I method relying upon estimates of births, deaths, and net-migration and (2) the Component III method relying solely upon 1990 and 2000 Census counts. From an April 1, 2000 base, each method is used to make estimates moving forward to an April 1, 2010 estimate that is compared to the results of the 2010 Census. The two methods are compared in terms of accuracy and bias using both absolute and algebraic mean and median percentage errors. Results are reviewed and discussed in light of their implications for applied demographers tasked with making small-area demographic estimates.     

Estimating Mortality Level for Small Populations: An Evaluation of a Pair of Two-Census Methods

A pair of two-census methods of estimating mortality levels are tested with simulated census data. The populations considered range in size from 250 to 1500 individuals of each sex; censuses were taken at intervals of five and ten years. In general, the methods are resistant to bias, and yield variances similar in magnitude to those obtained using vital registration data and life table techniques for censored data. The two-census methods represent a substantial improvement over the techniques of mortality estimation previously available for small populations, since two reliable censuses are more likely to be available for these populations than complete vital registration.     

Comparing the U.S. Decennial Census Coverage Estimates for Children from Demographic Analysis and Coverage Measurement Surveys

Following every U.S. decennial census since 1960, the U.S. Census Bureau has evaluated the completeness of coverage using two different methods. Demographic analysis (DA) compares the census counts to a set of independent population estimates to infer coverage differences by age, sex, and race. The survey-based approach (also called dual system estimation or DSE) provides coverage estimates based on matching data from a post-enumeration survey to census records. This paper reviews the fundamentals of the two methodological approaches and then initially examines the results of these two methods for the 2010 decennial census in terms of consistency and inconsistency for age groups. The authors find that the two methods produce relatively consistent results for all age groups, except for young children. Consequently, the paper focuses on the results for children. Results of the 1990, 2000, and 2010 decennial censuses are shown for the overall population in this age group and by demographic detail (age, race, and Hispanic origin). Among children, the DA and DSE results are most inconsistent for the population aged 0–4 and most consistent for ages 10–17. Results also show that DA and DSE are more consistent for Black than non-Black populations. The authors discuss possible explanations for the differences in the two methods for young children and conclude that the DSE approach may underestimate the net undercount of young children due to correlation bias.     

What is natural fertility? The modelling of a concept

The value and importance of the concept of natural fertility have been widely debated since Henry's work in the late 1950s. Whereas Henry regarded natural fertility largely as a useful concept for model building, Coale-Trussell demonstrated that this concept could also be used to analyze patterns of age-specific fertility. The set of age-specific marital fertility schedules assembled by Henry and then used by Coale and Trussell involved largely small populations drawn from disparate sources. Nonetheless, from this diverse and fragmentary data, Henry was able to construct a standard of natural fertility which, in the operational form developed by Coale-Trussell, has proved remarkably general in its application and utility. This in turn suggests that the physiological forces shaping fertility are exceedingly strong, especially the incidence of physiological sterility. There appears to be no single universal pattern of natural fertility. Rather, there is a set of closely related age profiles, the exact shape of which is determined by specific behavioral and social factors that influence childbearing. The increase in physiological sterility with age serves to give an upper limit to fertility at each age, while other factors determine how close a given population comes to that maximum. Although no society has ever demonstrated Henry's ideal notion of a purely physiological fertility pattern, the effect of the intervening factors is often weak. In terms of the Coale-Trussell model, maximum likelihood estimation offers the most informative method of implementation and a time series for 1 population is more readily interpretable than a cross-section comparing several populations.     

On the theory of stable populations: A new and elementary proof of the theorems under weaker assumptions

Expositions and elementary proofs are given for the basic theorems of stable population theory: That a population subjected to vital rates (not necessarily constant over time) satisfying certain postulates will eventually "forget" its original age distribution and take on one (not necessarily constant over time) which depends only on its history of agespecific vital rates, a process called "weak ergodicity." That consequently the subsequent birth, death, and growth rates (none of these necessarily constant over time) depend only on the history of age-specific vital rates and not on the original age distribution. And, in particular, that these results apply to the special case, herein called "classic" stable population theory, in which the age-specific vital rates are constant over time, and in which after the "forgetting" takes place the subsequent age distribution and birth, death, and growth rates all become constant. This formulation of the theory differs from previous ones in two respects: First, the postulates required are weaker, and hence the theorems more general, than previously; in particular, this formulation permits the highest age of childbearing to change from cohort to cohort, which is important for populations practicing contraception. Second, none of the advanced mathematics used in previous formulations is needed; only the manipulation of sums and inequalities from high school algebra and the concept of "limit" from freshman calculus are required.     

Age structure of six populations of old-field mice,Peromyscus polionotus

Summary An accurate age-estimating technique, based on biochemical changes in eye lens protein, was used to study age structures of six populations of the old-field mouse,Peromyscus polionotus. A new mathematical procedure permitted quantitative comparisons of these populations. Four inland populations had essentially the same median ages (75–84 days), maximum ages (248–297 days) and relative production rates (56–58% of the surviving population had been born in the 100 days prior to sampling). Approximately 50% of the females were old enough to have weaned a litter. One inland population had a lower median age (49 days), a lower maximum age (181 days) and a higher relative production rate (73%). Relatively fewer females (38%) could have weaned a litter. The single beach population was also different, with higher median age (180 days), and lower relative production rate (2%). All females were old enough to have weaned a litter. Maximum age was essentially the same as for the four similar, inland populations. Factors which may have contributed to observed differences in these populations are discussed.     

Estimating African-American mortality from inaccurate data

This paper evaluates the quality of vital statistics and census data for estimating African-American mortality over a period of six decades. The authors employ intercensal cohort comparisons and extinct generation estimates to demonstrate that conventionally constructed African-American death rates may be seriously flawed as early as age 50. Using the crude death rate at ages 50+ for 1978-1982 in conjunction with estimated growth rates and two model life table systems, the authors estimate black age-specific death rates in 1978–1982. These results suggest that if a racial crossover in death rates occurs, the age pattern of mortality among African-Americans must be far outside the range observed in populations with more accurate data.     

Demography,Education, and Democracy: Global Trends and the Case of Iran

Reconstructions and projections of populations by age, sex, and educational attainment for 120 countries since 1970 are used to assess the global relationship between improvements in human capital and democracy. Democracy is measured by the Freedom House indicator of political rights. Similar to an earlier study on the effects of improving educational attainment on economic growth, the greater age detail of this new dataset resolves earlier ambiguities about the effect of improving education as assessed using a global set of national time series. The results show consistently strong effects of improving overall levels of educational attainment, of a narrowing gender gap in education, and of fertility declines and the subsequent changes in age structure on improvements in the democracy indicator. This global relationship is then applied to the Islamic Republic of Iran. Over the past two decades Iran has experienced the world's most rapid fertility decline associated with massive increases in female education. The results show that based on the experience of 120 countries since 1970, Iran has a high chance of significant movement toward more democracy over the following two decades.