Parity Progression Ratios Research Articles

Deux ou trois enfants ?

La politique familiale francaise a toujours apporte un soutien particulier aux familles ayant au moins trois enfants, et tout particulierement dans les annees 1978-1982. Les auteurs s’interrogent sur l’efficacite de cette politique, en comparant le niveau de la fecondite de rang 3 ou plus en France et en Europe occidentale et en observant l’evolution de la proportion de meres de deux enfants ayant eu un troisieme enfant (probabilite d’agrandissement A2) depuis les annees 1970. Il apparait ainsi que cette politique ciblee sur le troisieme enfant a eu une influence sur la frequence de ces naissances, mais que cet effet est faible et difficile a quantifier. L’article s’interesse ensuite aux caracteristiques associees a la probabilite d’agrandissement A2. Ce sont l’âge a la deuxieme naissance, la duree de l’intervalle entre la premiere et la deuxieme naissance et la nationalite qui determinent le plus fortement cette probabilite. Toutes les autres variables examinees (le sexe des deux premiers enfants, la taille de la fratrie d’origine, l’histoire conjugale, la trajectoire professionnelle des meres, le niveau du diplome et le groupe socioprofessionnel de chacun des conjoints) sont significatives, meme apres controle des effets de structure. Les tendances recentes, et en particulier l’elevation de l’âge a la deuxieme naissance, impliquent une reprise de la baisse de la probabilite d’agrandissement des familles de deux enfants.

Regional fertility trends in Mozambique

This article increases our knowledge of Mozambique's demography by assessing the nature and magnitude of fertility decline, using the 1980 and 1997 censuses and the 1997 Demographic and Health Survey. Several robust methods, including P/F ratios from census and birth history data, the own-children procedure (census data), and estimates of censored parity progression ratios (adjusted for truncation bias) are used to identify fertility trends. Regional differences in fertility trends are discussed in the light of the proximate determinants of fertility. Fertility decline has started in Mozambique but the magnitude of the decline differs among the three administrative regions in the country. In Southern Region the fertility decline is well established, while in Northern and Central regions the decline is still incipient.

Japan’s changing fertility mechanisms and its policy responses

This paper discusses Japan’s decline in fertility over the past 50 years. The change in Japan’s postwar fertility is analysed using formal demographic tools such as parity progression ratios and decomposition methods. The analytical results show that before the oil crisis of 1973, the reduction in marital fertility played a dominant role, while the delayed timing of marriage has been a principal factor since the mid-1970s. The delayed timing of first and second births has also played a relatively important role in determining actual fertility levels in the 1990s. The paper examines various socio-economic factors contributing to these demographic shifts over time in postwar Japan. A number of policies and programs implemented over the past decade by the Japanese government to boost fertility are briefly described, together with their limitations.

Algorithm for decomposition of differences between aggregate demographic measures and its application to life expectancies, healthy life expectancies, parity-progression ratios and total fertility rates

A general algorithm for the decomposition of differences between two values of an aggregate demographic measure in respect to age and other dimensions is proposed. It assumes that the aggregate measure is computed from similar matrices of discrete demo

Sterility in Zambia

Background : Several regions such as Zambia in sub-Saharan Africa experience very high levels of sterility. Current explanations for high levels of sterility in Zambia have focused on biological determinants and have paid little attention to the plausible effects of social determinants of sterility. Aim : This study has two objectives. The first objective is to examine the extent of sterility in Zambia during 1980 and 1990. The second objective is to assess the contribution of selected social determinants to the current levels of sterility in Zambia. Subjects and methods : Sterility among women in Zambia is calculated for two periods in 1980 and 1990 using census data. The study used parity progression ratios for the calculation of sterility rates. Selected social determinants of Zambian sterility were obtained from the Demographic Health Survey (ZDHS). Net effects of selected social determinants were examined using logistic regression. Results : High sterility levels were found in a few Zambian Provinces. During 1980 and 1990, the rates for North Western, Eastern and Western provinces remained considerably higher than for other Zambian provinces. It was found that social level variables remained strong and significant even after controlling for the effects of incidence of biological factors such as sexually transmitted diseases (STDs). Conclusions : The findings of the study support the importance of developing social policies for eradicating sterility. The argument that sterility is biological and that it is not amenable to social interventions perhaps needs revision in the light of the findings of this study.

Puberty and the family formation process in Sudan: age-at-menarche differential fecundity hypothesis revisited.

This paper revisits and extends an inquiry on the age-at-menarche differential fecundity hypothesis. Earlier studies have interpreted the difference in the onset of female pubertal maturation as indicative of biological differences in fecundity between early and late menarcheal women. Using the WFS data for Sudan, the authors address the entire reproductive life of the women in terms of their transition from one parity to the next, as well as the speed with which birth intervals are closed, as a way to infer biological fecundity among the women. The study concludes that there is little evidence that early menarcheal women are more fecund than their late puberty counterparts.

Fertility of Australian birth cohorts: Components and differentials

The paper examines the change in the level and pattern of fertility that took place in the post-1971 period, and the downward completed fertility of successive generations of Australian women born since 1933–37. The change in cohort fertility is assessed in terms of the cohort parity progression ratios, and the four components of cohort total fertility: the proportion of women who proceeded to have a birth, mean age at first birth, mean age at last birth, and average interbirth interval for women who had at least two births. The other aspects discussed are the cohort fertility differentials and the implications of the current trends for future fertility in Australia.

Demographic Data Analysis in Less Developed Countries: 1946–1996

This paper reviews the development of indirect techniques for estimating vital rates in the developing world from census and survey data. The methods considered include the following: the exploitation of age distributions using the ‘own children’ method to estimate age-specific fertility rates by characteristics of the mother; the P/F ratio method for estimating current fertility and its extensions; the calculation of parity progression ratios to detect changes in family-building patterns following the adoption of contraception early in the transition process; methods for estimating childhood and adult mortality, including maternal mortality, from data on the survival of close relatives; the derivation of life tables from such estimates; and the correction of death rates using ‘growth balance methods’. The paper concludes with a section on possible future improvements in estimation techniques.

Fertility in England and Wales: a fifty-year perspective.

This paper provides a detailed account of fertility levels and trends in England and Wales since 1938, with a briefer coverage of a much longer time-span. The paper is concerned both with the measurement of fertility and with understanding the observed fertility behaviour. We lament and correct the failure of demographers to apply measurement tools available since the 1950s to the analysis of fertility in England and Wales, with a particular emphasis on adjustment of period measures and period parity progression ratios and show how some of the grosser errors of analysis and interpretation might have been avoided by earlier use of these approaches. We also relate these estimates to more recent ones. Once a clearer account of trends has been established, the paper goes on to reinterpret and explain the baby boom and baby bust. The conclusion looks at future prospects for fertility.

Whose Reality? Local Perceptions of Fertility Versus Demographic Analysis

Single-round demographic surveys of three Malian populations showed substantial fertility differentials, with much lower fertility in the two nomadic pastoral Kel Tamasheq populations than among the sedentary cultivating Bambara. Demographic analysis explained these fertility differentials by different marriage patterns, dominated by the structural effects of Kel Tamasheq monogamy which maintains a large group of currently unmarried women. This contrasts with the Kel Tamasheq's own pre-occupations with their low fertility which they ascribe to pathologically induced subfecundity and sterility. Parity progression ratios and birth-interval distributions are used to examine the degree to which the Tamasheq perceptions of their own fertility behaviour can be demonstrated by using the demographic data. The importance of the different perspectives and outcomes is discussed, with the need for taking into account local concerns both in analysis and ultimate policy interventions.

Using Parity-progression Ratios to Estimate the Effect of Female Sterilization on Fertility

In this article, a new methodology that employs parity-progression ratios to estimate the effect of female sterilization on fertility is described, and results using data from Ecuador are compared to those obtained using a previously existing approach that classifies women by marital duration. The methods differ in how they disaggregate marital fertility and in the assumption they make about what the subsequent fertility of sterilized women would have been if they had not been sterilized. The analysis of the Ecuadoran data shows that the estimate of births averted by sterilization has diminished over time, even as sterilization prevalence has been increasing. This situation is attributed to a decline in the fertility of nonsterilized women resulting from increased use of reversible methods of contraception.

Taiwan's Transition from High Fertility to Below-Replacement Levels

This article compares the fertility experience of Taiwanese in the eight years since the total fertility rate reached 2.1 with that before fertility reached replacement levels. During the earlier period, two-thirds of the fertility decline resulted from falling marital fertility and one-third from higher age at marriage. The changing age distribution retarded this decline. Since 1983, the further decline to 1.7-1.8 has been entirely the result of the trend toward later marriage. Older age distributions now facilitate the decline. Births postponed by those marrying later make the conventional TFR misleading. Computation based on parity-progression ratios raise TFRs from 1.7 to 2.0, a number less alarming to policymakers. Contraceptive prevalence is at saturation levels in all major populations strata. The "KAP-GAP" has disappeared. What would have happened without Taiwan's effective family planning program is impossible to determine, but clearly, contraceptive services supplied by the program were the major proximate cause of Taiwan's fertility decline.

Determinants of the Decline in Parity Progression Ratios in China, 1979-1984: A Factor Analysis of Provincial Data

Provincial data for China are used to examine the interrelationships between socioeconomic development family planning and changes in parity progression ratios between 1979 and 1984 using factor analysis and multiple regression analysis. The results indicate that at the provincial level a decline in progression from first births to second births (indicating acceptance of the one-child family norm) depended largely on the provinces level of socioeconomic development. In contrast the family planning program exerted the most significant influence on the decline in progression from second births to third births (and probably to higher parities as well) independent of socioeconomic conditions. (SUMMARY IN FRE AND SPA) (EXCERPT)

Decline in Fertility Among Japanese Women Attributed Not to Contraceptive Use but to Late Age at Marriage

Fertility decline in Japan resulted in a 1990 total fertility rate (TFR) of 1.5 children per woman in a lifetime. The high marriage age of 27 years is considered the most important factor influencing fertility decline. The proportion of women who never marry has tripled over the past 20 years (4% in 1973 and 12% in 1990). Later marriage age and never married status are attributed to disenchantment with marriage rising costs of childrearing and increasing educational and employment prospects for women. The trends in TFRs and the parity progression ratio have been similar since 1947. The mean number of children among women aged 25-29 years was 1.4 in 1971 and 1.3 in 1992. The mean desired family size decreased during the same period from 2.6 children to 2.4 children. Differences over time have occurred in the number of couples remaining childless and the number having only one child. Marital first births declined from 94% in 1973 to 88% in 1990. The number of women with one child decreased from 89% to 83% during the same period. Among 1000 hypothetical women the current parity progression ratios would be 12% never marrying 10% marrying and childless 13% marrying and with one child 41% marrying and with 2 children 20% marrying and having 3 children and 3% with 4 or more children. Urban and rural differences and differences in educational status have almost disappeared over time. The most dramatic change in marital patterns has been among women aged 20-24 years; 30% of women aged 20-24 years in 1975 and only 14% in 1990 married. Among women aged 25-29 years the decline was from 70% to 60%. Marital fertility has changed very little and the changes in marital fertility have accounted for 86% of the change in TFR between 1950 and 1973. Between 1980 and 1990 marital fertility would have raised TFR without the impact of delayed marriage. Education has an impact on the transition from a single state to a first marriage. Policies to increase fertility in Japan would have to be directed to making marriage more attractive and improving work conditions.

Changes in fertility relative to starting, stopping, and spacing behaviors in a migrating Mennonite community, 1775-1889.

Fertility change over time in a migrating Mennonite church congregation is reconstructed through genealogies developed from church registries of vital events during 1725-1924. The congregation was located in Prussia from 1725-1821, in Russia from 1822-1874, and in Kansas, U.S.A., from 1875-1924. Age-specific marital fertility rates were relatively low and usually peaked for women aged 25-29. Total fertility rates ranged from 1.19 to 5.29. These relatively low figures for a natural fertility population may partly reflect underreporting of births and deaths of infants, but it also reflects the heterogeneity in fertility evident for this population. Some women had many children while others were having either few or none. This pattern changed twice. Fertility was lowest during residence late in Prussia and early in Russia, peaked during residence late in Russia, and has decreased slightly for women born in the United States.

The Resumption of Fertility Decline in Japan: 1973-92

This article analyzes the fertility decline in postwar Japan especially since 1973 and the demographic and socioeconomic factors contributing to it. The analysis based primarily on period parity progression ratios suggests that Japans fertility decline since 1973 has occurred mainly because of postponement of marriage and first birth and declines in ratios of progression to marriage and first birth. It is shown that womens rising educational attainment plays an important role in inducing the new marriage and fertility pattern. The effect of womens education is associated with a number of related socioeconomic changes including rising wages of women and higher opportunity costs of marriage and childbearing as well as changes in values. (SUMMARY IN FRE AND SPA) (EXCERPT)

Parity Progression and Birth Intervals in China: The Influence of Policy in Hastening Fertility Decline

Period parity progression ratios and interval distributions for China were estimated using parity specific birth probabilities and time since last birth a method used by Henry. The objective was to provide additional evidence of the role of and program efforts in contributing to Chinas fertility decline. Causation is inferred according to the timing magnitude and direction of fertility changes. Retrospective data were obtained from the National Fertility and Birth Control Survey in 1988 (2/1000 survey). Analysis was conducted on time series data on age at marriage and birth intervals at the national level for cities towns and counties and for the provinces of Jilin Shaanxi Jiansu and Guangdong. City refers to the urban unit excluding rural areas. The provinces reflected different levels of development and fertility patterns. The sample included women aged 15-57 years; since all Chinese women would have their first birth before age 35 there would be negligible age selection bias for first births in the years 1966-1987. Age selection bias for higher order births may be slightly affected in the earlier period but the year-to-year fluctuations would be unaffected. Older women underrepresented due to mortality were calculated using the female life table methods of Coale and Zhang and Lu; the effects were found to be quite modest. The findings show significant variation in mean age at first marriage which can be plausibly interpreted as a response to the government in the 1970s of the longer later fewer policy and in 1979 of the 1-child policy. There was an abrupt increase and a leveling off at 23 years of age which was the mean age required by for the period 1970-75. Relaxation of age at marriage restrictions and the introduction of the 1-child was reflected in the decrease to 22 years between 1979 and 1981 and stabilization through the 1980s. The use of the life table method for calculating the mean age at marriage provides an analysis without the influences of population by age and marital status. Separate analyses were conducted for marriage to first birth first to second second to third and fourth and high order births; and age at marriage in the four provinces. There was glaringly apparent evidence that the period parity progression ratios and mean birth intervals show the impact of the 2 policies on births which is roughly calculated at 60% attributed to and 40% to other factors.

Estimation of Parity Progression Ratios from Survey Data on Birth Intervals in Egypt

Estimation of Parity Progression Ratios from Survey Data on Birth Intervals in Egypt

Estimation of parity progression ratios from the truncated distribution of closed and open birth intervals

A procedure to estimate parity progression ratios in a population from the truncated distribution of open and closed birth intervals is presented. The approach is quite simple in computation and data needs. It does not require any separate data on age at last birth to the women of completed fertility as in earlier methods. The procedure is illustrated with an observed set of data.

Age at last birth and its components

This paper examines the ways in which the behavior of twentieth century cohorts of American women changed simultaneously in the three components of fertility that determine age at last birth--age at first birth, spacing between subsequent births, and parity progression ratios of subsequent births--to produce changes in the timing of the completion of childbearing. It decomposes changes in the mean age at last birth among cohorts and between whites and nonwhites to changes in these three components. To perform these analyses, we developed and applied a method to estimate the distributions and means of ages and last births, birth intervals, and parity progression ratios from age- and parity-specific fertility rates available from vital statistics data. Results show that the cohorts increased and decreased their age at first birth, birth intervals, and parity progression ratios of lower and higher birth orders in almost every possible combination so as to achieve a relatively young age at final birth.