Census Age Distributions Research Articles

Demographic assessment and adjustment of census age distribution in selected West African Countries

Context/background: Despite the public acknowledgment of improvement in sub-Saharan African censuses and surveys in the recent time, the quality of age-sex data still remains relatively poor. This study assessed the quality of reported age-sex data in selected West African countries. Data source and methods: We utilized the available recent West African census data to address the study objective. Data adjustments were made using the UN-moving average technique, Carrier Far-rag, Karup-king newton and Arriaga methods. Results: First, the age- distribution in five years was examined for errors. The UN-Age-sex accuracy index showed that all the selected countries had inaccurate age-distribution, with the exception of Cameroon (2005) and Senegal (2002) censuses which revealed a lesser distorted age- distribution. Utilizing the strong smoothing techniques, the results showed that virtually all the censuses were plaqued with the overestimation error at older ages, particularly the female population. The error margin ranged between 10-25%. Conclusion: The study concludes that inaccuracies in West African census data persist and recommends more quality age-sex data in region.

Adjusting the general growth balance method for migration

Death distribution methods proposed for death registration coverage by comparison with census age distributions assume no net migration. This assumption makes it problematic to apply these methods to sub-national and national populations affected by substantial net migration. In this paper, we propose and explore a two-step process in which the Growth Balance Equation is first used to estimate net migration rates, using a model of age-specific migration, and then it is used to compare the observed death rates over successive ages against residual estimates made up by the entry rate plus the net migration rate minus the growth rate. This methodology is predicated on the observation that migration rates have a very different age pattern from death rates; it is only when this condition is true that net migration and deaths can be distinguished. The procedure proposed here works reasonably well in populations that generally have good data and rather high net migration rates. There is no reason to prefer the revised migration model over the original Rogers-Castro formulation.

Risk patterns of multiple myeloma in Los Angeles County, 1972–1999 (United States)

To describe the risk patterns of multiple myeloma in Los Angeles County (LAC). Incident multiple myeloma cases diagnosed from 1972 to 1999 were ascertained by the population-based cancer registry for LAC. Average annual age-specific and age-adjusted incidence rates (AAIR), standardized to the 2000 US census age distribution, were calculated using age-, race-, sex- and socioeconomic status (SES)-specific denominators estimated for all years from US census data for 1970, 1980 and 1990. Odds ratios (ORs) for risk by birthplace and religion were estimated using multivariate logistic regression, comparing multiple myeloma patients with other cancer patients. All groups experienced increasing incidence with age; African-Americans experienced the steepest increase which began a decade earlier compared to other groups. Overall incidence rates were 50% higher among males (n = 4,692) than females (n = 4,343) (p < 0.05). AAIRs were highest for African-Americans, followed by Spanish-surnamed whites (SSW), non-Spanish-surnamed whites (NSSW), Filipinos and other Asian groups. Among African-Americans, incidence rates increased with increasing SES. US-born SSW had 14% lower risk compared to non-US born SSW (OR = 0.86, 95% confidence interval [CI] = 0.74-0.99]. Jews had an 11% higher risk compared to Protestants (OR = 1.11; 95% CI = 0.99-1.24). Risk patterns suggest a role for both environmental and genetic factors.

Prevalence of anemia in children 6-59 months old in the state of Pernambuco, Brazil.

To determine the prevalence of anemia in children 6-59 months old in Pernambuco, a state in northeastern Brazil, so as to help guide health and nutrition policies there. In 1997 a representative sample of 777 young children had their hemoglobin concentration measured. The sampling process was in three stages. First, 18 municipalities were randomly selected to represent the state and its three geographic areas (metropolitan region of Recife, urban interior, and rural interior). Next, using census lists, 45 census sectors were randomly chosen. Finally, 777 children aged 6-59 months old were selected. Blood was collected by venipuncture, and hemoglobin was measured with a portable hemoglobinometer. In the analysis, prevalence was weighted to reflect the census age distribution. The prevalence of anemia among children 6-59 months old was 40.9% for the state as a whole. Prevalence in the metropolitan region of Recife was 39.6%, and it was 35.9% in the urban interior. The rural interior had the highest prevalence, 51.4%. Prevalence was twice as high in children aged 6-23 months as among those 24-59 months old, 61.8% vs. 31.0% (chi 2 = 77.9, P < 0.001). The mean hemoglobin concentrations in the younger and older age groups were 10.4 g/dL (standard deviation (SD) = 1.5) and 11.4 g/dL (SD = 1.4), respectively. There was no statistically significant difference between the sexes in terms of prevalence. This is the first statewide assessment of anemia prevalence among young children in Brazil. Given the very high prevalence of anemia among the children studied in Pernambuco, especially those in the age group of 6-23 months, public health interventions are needed.

Consistent correction of data for aboriginal populations.

"A consistent correction procedure is used to determine improved, consistent estimates by sex of census age distributions, intercensal births, intercensal deaths and net migration by age for the Aboriginal populations of the Northern Territory, South Australia and Western Australia during the period 1986-91. Undercount estimates and life tables show the Aboriginal populations to have lower coverage in statistical collections and much higher death risks than the total Australian population. Inter-regional net migration estimates show that component of change can no longer be ignored."

Intercensal Change and the Indirect Estimation of Mortality: The Case of Pakistan

"In a country such as Pakistan, where there is no vital registration system, estimating mortality levels and trends can be difficult. One way we can learn about mortality is to use indirect estimation techniques on census age distributions. This paper applies some of these techniques and evaluates the quality of the census data in the process." Problems of relative coverage in the 1972 and 1981 censuses and changes in age-reporting preferences are discussed. Comments by Mohammad Afzal are included (pp. 583-5).

Examination of the generalized age distribution

The formula for the age distribution and other relationships that follow from it for any (non-stable) population presented by Preston and Coale are significant contributions to demography. The formulas summarize the relationships among various demographic measures precisely, and are formally analogous to the relationships that hold for stable populations. The significance of these formulas cannot be overstated; they allow us to understand clearly the relationships among demographic measures in any arbitrary population. However, when it comes to using them for estimating demographic measures when census data are defective, the method of estimation is still affected by defective data. The reason is that the series of age-specific growth rates reflects the observed census age distributions exactly so that any defects in the census data are summarized in the growth rates. This paper begins with the formulation of the discrete version of the "new synthesis" developed by Preston and Coale. With the discrete formulation, the three kinds of errors introduced when the continuous time formulas are applied to real data can be avoided. Then it is pointed out that when two accurate census data are available, the Preston-Coale procedure of "estimating" the age distribution at the second census is equivalent to checking the identity of the age distribution formula. Also "estimating" mortality by the procedure of Preston-Coale is shown to be equivalent to obtaining mortality directly from intercensal survival rates. That the procedure which involves the age-specific growth rates is equivalent to those that involve the intercensal survival rates may have escaped notice because there are no a priori constraints for patterns of age-specific growth rates to follow. The irregularity in growth rates due to defective data are not distinguishable from true irregularity that exists in the population, contrary to the well-known regularity in the pattern of survival rates in human populations.

Estimating the completeness of death registration

Summary Death registration statistics, even when incomplete, can provide valuable information about mortality. In particular, the age structure of deaths can be used to estimate the completeness of registration, provided that this completeness does not vary substantially with age. Two methods of estimating the completeness of death registration from the distribution of deaths by age are described. The first is derived from stable population theory and requires an estimate of the rate of natural increase of the population, as well as assuming stability. However, the technique can also be used to generate simultaneously estimates of the rate of natural increase and of death registration completeness. The second method which requires two census age distributions and intercensal deaths by age, estimates the relative enumeration completeness of the two censuses as well as the completeness of death registration and requires only that the population be closed. Results are sensitive to overstatement of age. The methods are illustrated by being applied to figures from Thailand for the period 1960-70 and are found to work satisfactorily.

Model Migration Schedules and Their Applications

This paper considers and contrasts two alternative approaches for capturing the regularities exhibited by age patterns in observed migration rates. The mortality approach is considered first and it is shown how such an approach may be used to infer migration flows from two consecutive place-of-residence-by-place-of-birth census age distributions. The fertility approach is considered next, and techniques for graduating migration age profiles are described. The advantages and disadvantages of both approaches are then briefly assessed.

Estimation of demographic measures for India, 1881–1961, based on census age distributions

Abstract India is one of the very few developing countries which have a relatively long history of population censuses. The first census was taken in 1872, the second in 1881 and since then there has been a census every ten years, the latest in 1971. Yet the registration of births and deaths in India, even at the present time, is too inadequate to be of much help in estimating fertility and mortality conditions in the country. From time to time Indian census actuaries have indirectly constructed life tables by comparing one census age distribution with the preceding one. Official life tables are available for all the decades from 1872-1881 to 1951-1961, except for 1911-1921 and 1931-1941. Kingsley Davis(1) filled in the gap by constructing life tables for the latter two decades. He also estimated the birth and death rates ofIndia for the decades from 1881-1891 to 1931-1941. Estimates of these rates for the following two decades, 1941-1951 and 1951-1961, were made by Indian census actuaries. The birth rates of Davis and the Indian actuaries were obtained basically by the reverse survival method from the age distribution and the computed life table of the population. Coale and Hoover(2), however, estimated the birth and death rates and the life table of the Indian population in 1951 by applying stable population theory. The most recent estimates of the birth rate and death rate for 1963-1964 are based on the results of the National Sample Survey. All these estimates are presented in summary form in Table 1.

Estimation of Demographic Measures for India, 1881-1961, Based on Census Age Distributions

Estimation of Demographic Measures for India, 1881-1961, Based on Census Age Distributions

The Pattern of Age-Specific fertility rates

A study of the pattern of age-specific fertility rates by five-year age-groups has revealed the possibility of using the Pearsonian type I curve as a graduating equation. Such distinctions have been examined for fifty countries having high, medium, and low fertility rates. Results have been found to be quite satisfactory, even when, for purposes of simplicity, the parameters have been restricted to depend on the first two moments, instead of the first four. The number of independent parameters has thus been reduced to only three, and method shave been suggested for their estimates, using ancillary information which is usually provided in the census reports. The findings seem to be particularly useful for countries lacking effective registration systems of vital events such as births related, as they are, to the age of the mother.In short, the determination of a series of age-specific fertility rates depends primarily on the modal fertile age (a1) and on one of the two exponents (m, or m2) of the type I distribution. It has been shown that the proportions of women married in the age groups 20-24 years and 25-29 years can be used for approximate evaluations of both of these parameters. While estimates of a, and m, are sufficient to generate a relative distribution of age-specific fertility rates, actual values can be obtained if, in addition, the annual number of births is either known or can be estimated from census age distributions of children.Modal distributions of relative values of age-specific fertility rates (such that the sum of these rates adds up to 100.0) have also been obtained for different combinations of al and m1, but are not shown here for lack of space. Once the estimates of al and m, have been made, the modal tables can always be referred to for the corresponding distributions of age-specific fertility rates.

Some Characteristic Features of Census Age Distributions in Illiterate Populations

Previous articleNext article No AccessCommentary and DebateSome Characteristic Features of Census Age Distributions in Illiterate PopulationsEtienne Van De WalleEtienne Van De Walle Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by American Journal of Sociology Volume 71, Number 5Mar., 1966 Article DOIhttps://doi.org/10.1086/224174 Views: 80Total views on this site Citations: 5Citations are reported from Crossref Copyright 1966 University of ChicagoPDF download Crossref reports the following articles citing this article:Frank Hobbs Age and Sex Composition, (Jan 2004): 125–173.https://doi.org/10.1016/B978-012641955-9/50041-2Pierre van der Eng Bridging a gap: a reconstruction of population patterns in Indonesia, 1930–61, Asian Studies Review 26, no.44 (Feb 2007): 487–509.https://doi.org/10.1080/10357820208713359Charles B. Nam, Gouranga Lal Dasvarma, Sri Pamoedjo Rahardjo The Changing Age Distribution in Indonesia and Some Consequences 1, Bulletin of Indonesian Economic Studies 27, no.22 (Aug 1991): 121–136.https://doi.org/10.1080/00074919112331336028Israel S. L. Sembajwe Education and accuracy of age reporting among Yoruba females in Western Nigeria, Social Biology 27, no.44 (Aug 2010): 294–303.https://doi.org/10.1080/19485565.1980.9988432Henry S. Shryock, Jacob S. Siegel Age Composition, (Jan 1976): 113–144.https://doi.org/10.1016/B978-0-12-641150-8.50012-3

Some Demographic Measurements for Egypt Based on the Stability of Census Age Distributions

Some Demographic Measurements for Egypt Based on the Stability of Census Age Distributions