Estimation of vital rates by means of monte carlo simulation

Monte Carlo simulation has been used to estimate age-specific fertility and mortality rates for a small population,the French-derived isolate of Northside on St. Thomas, U. S. Virgin Islands. Estimates were based on data collected in a household census and genealogical survey and on birth, death, and marriage records for the years 1916to 1966. During this 50-year period (in which the population size increased from 202 to 657), the numbers of births and deaths were too, small to estimate age-specific rates directly, and in addition, death registration was incomplete. Mortality rates were estimated using a simulation program in which mortality was the only stochastic variable. A model mortality schedule was chosen which most accurately reproduced the growth pattern of the population over the 50-year period. To estimate fertility rates, a more complex simulation model was used in which fertility, nuptiality, and mortality were random variables with probability distributions. Preliminary estimates of fertility were made from the birth records and used as input to this simulation program. Birth probabilities were adjusted empirically from one set of simulation runs to the next, until population growth rates, as well as other demographic characteristics, were similar in the real and simulated populations. The birth rates which produced the best fit to the real population data were taken as the estimated age-specific fertility schedule. To reproduce the real population age structure more closely, secular changes in birth probabilities were applied.     

A vital statistics-based procedure for estimating conception rates

A method for estimating conception rates, using vital statistics data, is developed and applied to data on five-year age groups of California women for 1971. The approach is deterministic and allocates total exposure time to the known pregnancy outcomes of live birth, spontaneous abortion, and induced abortion. The population at risk is defined to exclude women who are known to be sterile or sexually inactive. Early fetal loss, premarital conception, and contraceptive use are taken into account. Estimates are made of the fecundability which would obtain ifno contraception were used.     

Atechnique for estimating life expectancy with crude vital rates

This paper describes a method of estimating life expectancy at birth on the basis of crude vital rates. The method is derived from stable population theory and it furnishes good estimates insofar as the current crude vital rates of a population are close to its intrinsic rates. This condition is generally met in closed populations which have not experienced sharp movements in fertility. The method is useful for estimating life expectancy in developing nations with good sample registration systems but for which information on age is of poor quality. It is also useful for estimating the movement of life expectancy in certain European nations in the period prior to regular census taking. There are a number of nations and regions in Europe for which long series of birth and death rates are available but for which census age counts are widely spaced.     

Changing vital rates and age distributions

Abstract In a time of rapid change in birth and death rates demographers need to know the consequences of such changes for age distribution. Does the fall in death rates tend to make the age distribution older? It certainly enables individuals to grow older, but for population aggregates the effect depends on the ages at which mortality improves. Coale, Stolnitz, Schwarz, Lorimer, the United Nations and other writers have investigated trends in age-specific birth and death rates. In particular they have demonstrated that the falling mortality which is now nearly universal does not generally make the population older and sometimes makes it younger. The present article contributes a technique for further examination of this phenomenon.     

Estimates of vital rates for the Canadian Indians, 1960–1970

The present paper is an attempt to evaluate the registered data on Canadian Indians collected by the Department of Indian Affairs and Northern Development and to prepare vital rates for 1960–1970 using the adjusted data. A cursory examination of registered data for the purpose of developing various demographic indices and for making future estimates of population indicates certain anomalies that call for a careful appraisal of the data. The main problem is the inconsistency in the reporting of births, due largely to the late registration of births. One plausible reason for late registration may be the increased outward movement of Indians from their reserves. Indirect methods are used to adjust the number of births and infant deaths reported annually since 1960. On the basis of the adjusted data, vital rates for the Canadian Indians are calculated for the period 1960–1970. The crude death rate decreased from 10.9 in 1960 to 7.5 in 1970. The infant mortality rate registered a drastic decline, from 81.5 deaths per 1,000 births in 1960 to 34.9 in 1970. During this same time period the birth rate also declined, from 46.5 to 37.2.     

Crossovers that link populations with the same vital rates

"In this paper, we consider crossovers of demographic density distributions from...populations that have the same fertility and mortality rates. We focus on observed populations and their associated stationary and stable models, and on proportional distributions of persons, births, deaths and reproductive values....Three different populations were selected to represent a range of demographic behavior. Those populations are Japan 1963, a low mortality, low fertility population; Togo 1961, a high mortality, high fertility population; and the United States 1919-1921, a population whose fertility and mortality are intermediate."     

Optimal estimate of population age structure with varying vital rates

The author presents a method for estimating the age distribution of a population under varying vital statistics. "Some mathematical aspects of the method, as well as its applicability, will be discussed and numerical simulation will be run to illustrate the results and to compare the method with the traditional estimate of stable population theory...."     

New estimates of the vital rates of the United States black population during the nineteenth century

The difficulties of obtaining credible estimates of vital rates for the black population throughout the entire nineteenth century are overcome in this study. The methodology employed the notion of deviating networks of mortality rates for each general mortality level, which was taken from the United Nations studyThe Concept of a Stable Population. Period life tables and vital rates for intercensal periods were generated from the new estimates of the black population at each census date. The results of this study are highly compatible both with the life tables for the death-registration states in the twentieth century and the recent Coale and Rives reconstruction for the period from 1880 to 1970 and with several estimates of vital rates previously made for the mid-nineteenth century. This study places the mean life expectancy at birth for the black population during the nineteenth century at about 33.7 years for both sexes. The infant death rate (1000m (0)) is shown to have varied between 222 and 237 for females and between 266 and 278 for males. The intrinsic crude death rate centered on 30.4 per thousand during the century, while the birth rate declined from 53.2 early in the century to about 43.8 at the end.     

Annual fertility rates from census data on own children: Comparisons with vital statistics data for the United States

This paper begins by describing the procedure and data requirements for calculating annual fertility rates from census data on own children. Then, using data from the United States Censuses of 1960 and 1970, fully adjusted estimates are presented and compared with recorded vital statistics rates. Total fertility estimates derived from own children data for whites average less than two percent lower than the recorded rates- a difference that can be attributed partially to the fact that the estimates are adjusted for net census undercount but the recorded rates are not. Even without adjustments for mortality, children not living with their mothers, and net census undercount, the own children data estimates accurately replicate recorded trends (even though the levels are misspecified). The utility of own children data for the study of differential fertility is discussed.     

A method for deriving mortality estimates from incomplete vital Statistics

Summary Although they are available in many developing countries vital registration records are very little used for mortality estimation which is still mainly based on census returns. However, defective death records may yield accurate estimations of mortality. This procedure requires few data only; a sex-age distribution of the population (preferably at the middle of a period) and a sexage distribution of deaths, either derived from vital records or from census returns to questions relating to deaths during the preceding twelve months. This method is based on the observation that for a fixed age structure of the population, there is a one-one relation between the age structure of deaths (measured by the proportion of deaths at older ages) and the level of mortality (measured by the death rate above a certain minimum age). It is assumed that at ages above this minimum the rate of underregistration of deaths does not vary significantly with age. Therefore, the age distribution of registered deaths makes it possible to estimate the true proportion of deaths at older ages. This in its turn will permit the estimation of the true level of mortality, because of the relation which exists between age structure of deaths and level of mortality. The true level is then compared with the observed, to estimate the rate of underregistration, and observed age-specific death rates can be adjusted in the light of this knowledge.     

Canada's national vital statistics index

Study of population trends and social change in Canada will be facilitated through the development of a system of record linkage which has recently been introduced. It provides a means whereby all the vital records about particular individuals may be brought together through a single master index. The social usefulness of this instrument is only now beginning to be realized.     

Determinants of rural-urban migration in Ghana

Abstract In the 39 years between the 1921 and 1960 censuses, urban population in Ghana multiplied by nine while the population of the whole country only trebled. The major factor in urban growth was rural-urban migration and the reproduction of the migrants. In 1963 a survey consisting of a systematic sample of households in 45 rural centres, randomly chosen in Local Authority Areas selected in accord with the regional rural population distribution, reconstituted the rural population so as to include current migrants in the towns as well as those remaining in rural areas. For analysis 13,748 respondents were divided into 14 categories by ruralurban migration behaviour. At the same time a survey of urban population provided a check on rural-urban migration data. study of the propensity to migrate from rural to urban areas shows that this increases with the closeness of the rural area to a large town, the population size of the rural centre, the economic well-being of the rural household, the number of relatives already in the urban area, the individual's level of education, larger family size and probably lower birth rank, as well as exhibiting specific age and sex patterns. It is shown that only a minor role is played by occupation, conjugal condition and number of dependants. Various interrelations between these factors are discussed, and attention is given to the special importance of education in partially or wholly determining some of the other factors. Census data are used to demonstrate the effect of rural-urban migration in concentrating persons with certain characteristics in the urban areas.     

Sex preferences for children in Ghana: the influence of educational attainment

Education influences aspects of demographic behaviour and outcomes including a child sex preference. Sex preferences of children have been studied in different societies because of its associated social and demographic implications. Using the 2014 Ghana Demographic and Health Survey, we examined the association between educational attainment and sex preferences of children. Findings from the study indicated that there is preference for sons (26.1%) compared to daughters (17.4%). At higher levels of education, there is a higher likelihood for no preference for a sex of a child. Among the characteristics of respondents that influenced sex preferences are: gender, lineage, religion, occupation and desired family size. Acquisition of knowledge through education to some extent alter fertility preferences and hence the need to motivate individuals to attain some level of education.     

Ethnicity and fertility desires in Ghana

Journal of Population Research - The extant literature shows that fertility desires are an important indicator for understanding and predicting the future course of fertility; however, little work...     

Determinants Of Cumulative Fertility In Ghana

The relatively few studies conducted on fertility differentials in Ghana have not controlled for the effect of important demographic variables, such as age at first marriage and current age of respondent. This paper attempts a multivariate analysis of the relationship between cumulative fertility and age at first marriage, level of education, religion, form of marriage and residence of husband. Data drawn from a census sample survey in 1971 include 72,816 currently married females aged 15–49 years. Age at first marriage was inversely related to cumulative fertility. The differentials were more pronounced for older women. Among the older women, the differentials were larger for rural than urban women. There were also significant fertility differentials associated with level of education, religion and form of marriage. Husband’s residence was a poor predictor of cumulative fertility. As a policy measure, it is suggested that priority be given to providing young women with more education or employment opportunities as an alternative to early marriage.