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In Part I of this paper (published in the previous issue) we outlined the major contrasts in demographic experience between almost all areas of Scotland and most of England during the later nineteenth and early twentieth centuries. We also demonstrated the existence of significant regional differences within Scotland. In Part II. interpretations are offered for these various contrasts in experience. Four Scottish regional case studies are examined, each of which shows a different combination of nuptiality, marital fertility and out-migration. In studying each case, stress is laid on the ways in which the prevailing demographic regime, if it is examined as an interrelated whole, can be seen as involving highly appropriate adjustments to the ecological, economic, and institutional contexts of the region. In this approach, `innovation' aspects of the fertility decline are therefore played down: instead, for some parts of the country in particular, continued very high fertility among those who married is seen as a highly rational response to particular local social and economic situations which also encouraged very low nuptiality, and moderate or high levels of out-migration. The much lower nuptiality in Scotland compared to England is explained in part by reference to constraints on access to housing and the very limited availability of any support from the Poor Law, and in part through limited economic opportunities in a more slowly growing economy. [ABSTRACT FROM AUTHOR]

In the second part of this paper we take up some of the issues that were raised in the first, and suggest some explanations for the regularities identified in the pattern of infant- mortality decline. We begin by considering contemporary analyses of the infant- mortality problems especially under the headings of sanitary conditions and maternal care. We also deal with the relationships between fertility decline, improvements in women's education and living standards, and the decline of infant mortality. In the final section we provide an extensive summary and discussion of the whole paper. [ABSTRACT FROM AUTHOR]

Previous research on the relationship between extended family residence and fertility has produced conflicting findings. In the present paper, we avoid a major shortcoming of past work by focusing on residence and fertility at a given stage of the life-cycle, i.e. the stage following first marriage. Results show that residence with husband's parents reduces age at marriage. Residence with wife's parents shows no such consistent effect. No evidence was found to support the claim that extended family residence consistently affects the length of the interval between marriage and the first birth. These findings are consistent across four cultural/ethnic groups. [ABSTRACT FROM AUTHOR]

This paper was developed with two purposes in mind: first to extend the study of the family life cycle for this sub-population on the United States back to the 1800 birth cohort and secondly to examine the features of the family life cycle under conditions of high natural fertility. Evidence Consistent with a natural-fertility regime is presented using Mormon genealogies of married women who were born between 1800 and 1869. The family life cycle for this high-fertility population indicates how the reproductive potential of a population is tempered by life-cycle phenomena. Age at marriage greatly affects completed family size: Women who married by the age of 20 average about nine live births against an average of only six for women married at age 25. However. the age at birth of the last child is high and unrelated to age at marriage as would be expected under conditions of natural fertility. By using direct information on the age at death for these couples. we find that the average age at dissolution of the conjugal unit has not varied by more than a few years and has consistently been in the mid 60's. [ABSTRACT FROM AUTHOR]

This article presents the reply of the author and co-authors to an article about the analysis of differences in the fertility patterns between national populations and over time. In their comments to our paper Osona and Kohler make a number of interesting and potentially helpful points. While their comments do not, in general, appear to be in conflict with our opinions, we are concerned that they have misunderstood one specific point. In their first section, on the analytical relationship between Hadwiger parameters and demographic measures, the authors re-present some known results. Those results, of course, were not the essential point of our paper, which was concerned primarily with the analysis of differences in fertility patterns. The functions were fitted in order to gain understanding of the differences in the patterns between countries and periods. The correspondences between variables to which they refer were used in order to investigate the effects of departures from the models in cases of distorted distributions. In their section dealing with reparameterization the authors propose an alternative to our presentation of the Hadwiger mixture model. Their explicit interpretation of the Hadwiger parameters as the total fertility, the mean age at childbearing, and the variance of the fertility schedule is possibly a step forward for the use of the model in demography.

This paper presents estimates of the level and trend of the fertility of different ethnic minorities in the UK from the 1960s up to 2006. The fertility estimates are derived primarily from the Labour Force Survey using the Own-Child method, with additional information from the General Household Survey and vital registration data. Comparisons are made between the level of fertility of UK-born and immigrant mothers from minority groups, and the fertility of the populations in the country of origin. Total fertility in all groups has fallen from levels that were initially relatively high. That of some UK ethnic groups has already fallen to about the level of the UK national average (e.g., black Caribbean) or below it (e.g., Indian and Chinese). Only among Pakistani and Bangladeshi women does total fertility remain substantially above the national average despite a continuous decrease over the last 20 years. [ABSTRACT FROM AUTHOR]

This paper examines the past transition from low to high fertility which, in Indonesia as elsewhere, preceded the return to lower birth rates. Data from two parts of the island of Sulawesi where fertility rose during the colonial period are used to explain both why it rose, and why it was originally low. Economic conditions, it is argued, were the most important factors, affecting fertility via the supply of income and the demand for labour. Two schematic models of the 'first fertility transition' are proposed. In areas with low population densities and area-extensive forms of agriculture responsive to commercial stimuli, birth rates rose as the growth of commerce raised levels of prosperity, facilitated marriage, and undermined institutions such as debt-slavery which had previously acted to restrict marital fertility. In densely populated areas with labour-intensive agriculture and heavy state taxation in labour, fertility rose in response to demands for women's (and possibly child) labour that did not necessarily lead to gains in income. [ABSTRACT FROM AUTHOR]

Many scholars have argued that deliberate birth spacing may have played a role before and during the modern fertility transition. There are good historical and theoretical reasons for this view, but it has proved to be hard to demonstrate convincingly that birth intervals were in fact partly determined by attempts at deliberate fertility control. This paper suggests a method of securing evidence on the issue for married couples. The method is applied to three cohorts living in a Belgian town in the nineteenth century. The findings indicate that, even before the fertility transition, couples in the working class were controlling their fertility by deliberate spacing. [ABSTRACT FROM AUTHOR]

Inadequate data and apartheid policies have meant that, until recently, most demographers have not had the opportunity to investigate the level of, and trend in, the fertility of South African women. The 1996 South Africa Census and the 1998 Demographic and Health Survey provide the first widely available and nationally representative demographic data on South Africa since 1970. Using these data, this paper describes the South African fertility decline from 1955 to 1996. Having identified and adjusted for several errors in the 1996 Census data, the paper argues that total fertility at that time was 3.2 children per woman nationally, and 3.5 children per woman for African South Africans. These levels are lower than in any other sub-Saharan African country. We show also that fertility in South Africa has been falling since the 1960s. Thus, fertility transition predates the establishment of a family planning programme in the country in 1974. [ABSTRACT FROM AUTHOR]

This paper investigates the consequences of using different economic status proxies on the estimated impact of economic status and other determinants of fertility. Using micro survey data from Ghana and Peru, we find that the proxies for income that best predict fertility are a principal components score of the ownership of consumer durable goods and a simple sum of ownership of these durable goods, Furthermore, the choice of the proxy generally has a minor influence on the predicted effects of the control variables. We compare the results from using a restricted set of proxies, such as those available in the Demographic and Health Surveys, with the results obtained using a lengthier set of proxies. Our results suggest implications beyond fertility analyses by providing researchers with an awareness of the sensitivity of microanalyses to the treatment of economic status. Our results also suggest practical recommendations for the collection of survey data. [ABSTRACT FROM AUTHOR]

The decline of human fertility that occurred in Europe and North America in the nineteenth century, and elsewhere in the twentieth, remains a topic of debate largely because there is no accepted explanation for the event. This paper uses district-level data from Bavaria to study the correlates of the decline of fertility in that German kingdom in the nineteenth century, Bavaria's fertility transition was later and less dramatic than in other parts of Germany. Our results for Bavaria indicate that the European Fertility Project was right about the role of religion and secularization, but missed an important role for the economic and structural effects stressed by economic historians. [ABSTRACT FROM AUTHOR]

In 1945, at the end of the Second World War, Albania had the highest fertility in Europe with an average of more than six live births per woman. However when Albania emerged from behind the 'olive curtain' in 1990, fertility had fallen to three children per woman, despite a pro-natalist environment and in the virtual 'absence of Contraception and abortion. Nevertheless, after five decades, Albania's position at the top of the European fertility league remains unchanged. This paper documents the fertility transition in Albania during the period 1950-90 and places the demographic results in the context of recent socioeconomic and cultural change. [ABSTRACT FROM AUTHOR]

This paper reviews and interprets recent demographic trends and prospects in the two Irelands, North and South. We discuss both the influence of religion on demographic behaviour, and the impact of demographic trends on the distribution by religion. In the Republic of Ireland, we show that the long-standing gap in marital fertility between Catholics and others had virtually disappeared by the 1980s. In Northern Ireland the gap is still there in the 1990s, though considerably reduced. However, estimates of its size hinge on how the significant proportion of non-respondents to the census question on religion are allocated. We identify some peculiarities of the non-respondent population which imply that it was more `Catholic' in 1991 than first reports suggested. The Catholic share of Northern Ireland's population may accordingly be larger -42 to 43 per cent - than previously thought. In both communities, the future of the Catholic share depends less on fertility than on migration patterns. [ABSTRACT FROM AUTHOR]

The hypothesis that minority status creates social tensions that affect fertility behaviour attracted much attention during the late 1960s and l970s, but then disappeared after 1980. This sudden exit was due to a combination of methodological difficulties in distilling the independent effects of minority status from other socio-economic factors, weaknesses or ambiguities in the empirical record, and other difficulties. This paper examines a natural experiment that serendipitously by-passes more of these problems than has been heretofore possible - the attempt by Chinese in Malaysia to time births into the auspicious Year of the Dragon. A multivariate model shows that this unique fertility behaviour was more common in Malaysian districts with smaller proportions of Chinese, which suggests that minority status can directly affect ethnic identity. The results also highlight a paradoxical solution to a grander problem facing socio-demographic theory. Before we can posit that culture or values play an independent role in transitions to lower fertility, we should first trace a baseline definition of these values from the study of demographically trivial events. [ABSTRACT FROM AUTHOR]

In this paper growth rates, marriage patterns, fertility, mortality, population composition and urbanization in England and her American colonies in the seventeenth and eighteenth centuries are compared. The purpose is to see whether the colonists perpetuated English demographic patterns in the New World, or whether new environments led to new behaviour. The results are derived from numerous local studies, often based on family reconstitution. Taking into account regional variations in America, colonial demographic patterns were quite different from those in the mother country. [ABSTRACT FROM AUTHOR]

In this paper the author proposes an alternative formulation of Ryder's equations of demographic translation by constructing a filter which relates period and cohort-based parametric fertility schedules. The resulting filter is used to study fertility data from eight countries in Europe and North America. The author concludes that although a cohort-based model can explain all but the short-run variations in period fertility, the resulting model would have to be quite complex. In particular, it would need to explain the observed tendency for changes in the tempo and spread of cohort fertility to lead changes in the quantum of cohort fertility by several years. An analysis of the spectral properties of the translation filter indicates that a period-based model could easily produce this pattern. The fact that the period-based model provides a more parsimonious description of the observed patterns sheds doubts on the predictive value of cohort-based models of fertility. [ABSTRACT FROM AUTHOR]

Parity progression measures are uniquely suited to the study of fertility in China, because Chinese policies and programmes focus so closely on parity and birth order. In this paper we present period parity progression ratios for China and its urban and rural areas for the years 1955-81, using the birth history data from the one-per-thousand fertility survey of 1982. Our period parity progression ratios differ from those introduced by Henry in that they provide an overall level of fertility which may be compared with measures based on age-specific birth rates. We compare the two measures empirically for China, finding both similarities and divergences, and then analyse the relation between them. It is suggested that, where fertility is low and fluctuating, as in China, the parity-progression- based measures provide a substantially truer picture of fertility levels and trends than do age-based measures. [ABSTRACT FROM AUTHOR]

This paper challenges the widely held and influential view that the fertility transition is largely the consequence of changing parental demand for children brought about by changes in the economic costs and benefits entailed in childbearing. Using evidence from both historical and contemporary populations we argue that demand theories do not offer a plausible explanation of the fertility transition. Instead, we propose that ideational, rather than structural, economic change lies at the heart of the transition. In particular, we suggest that attitudes to birth control, broadly defined, play a crucial role. [ABSTRACT FROM AUTHOR]

The modernization of reproductive behaviour in the Netherlands was late and slow in comparison to other European countries. In this paper marital fertility (Ig) and nuptiality (Im) between 1850 and 1960 are described and analysed, in this way adding the Dutch case to the studies of the European Fertility Project. In the analysis a model is used in which economy, attitudes and infant mortality are the (clusters of) independent variables, and either Ig or Im is the dependent one. To avoid multicollinearity the interdependencies of the explaining factors are eliminated. An analysis is made of both the level and the development of fertility and nuptiality. The model used fits the data well, and the distinction between level and development is of great importance. If analyzed statistically the variance in Im and Ig between the provinces can for the most part be explained by the attitudinal factor, while when analyzing the changes in nuptiality and marital fertility the economic factor has the strongest explanatory power. [ABSTRACT FROM AUTHOR]

Stable population theory has recently been used to analyse the effects of changes in fertility and mortality on economic variables such as income per head. In this paper more general results are derived to describe the effects of changing vital rates on the variance and higher moments of the distribution of some age-dependent variable. Simple analytical expressions are derived which decompose the effects of changes in age structure into the effects on inter-cohort and intra-cohort variance. The results are easily applied to standard measures of the distribution of income. By combining the analytical results with actual age profiles of income and income variance from the United States and Brazil it is observed that both the magnitude and direction of the effects of population growth on measured inequality are sensitive to the specific age profiles used. The most surprising result is that the Brazilian age profiles suggest that higher growth rates may actually reduce measured inequality, although the effect is relatively small. [ABSTRACT FROM AUTHOR]

Earlier work by Page and Coale has estimated demographic indices of fertility and mortality for parts of Africa using the Sullivan modification of Brass's technique. The present paper presents modified and more accurate estimates of fertility and child mortality, not only for the sub-national units covered by Page and Coale but also for areas not covered by them. The present analysis which employs Trussell's refinement of Brass and Sullivan's techniques also includes improvements overlooked in earlier estimates. The salient finding that emerges is that while the Brass mortality technique is very powerful, his equally ingenious fertility technique is very weak and should not be relied on for estimating fertility parameters. [ABSTRACT FROM AUTHOR]

A population's growth potential is significantly underestimated by conventional calculations of population momentum which assume an immediate drop to replacement level fertility. Here we assume that the growth rate of births linearly declines to zero over a specified time interval, and find simple and intuitively meaningful expressions for the size of the ultimate birth cohort and the resultant population momentum. In particular, we find that the increase in the number of births over the transition is equal to growth at the initial rate for half the time needed to attain a constant birth level. Thus our formula readily calculates the growth potential of a population under a gradual approach to stationarity without the need for a numerical projection. Calculations for actual and hypothetical populations are presented to show the demographic impact of such gradual approaches to zero growth. [ABSTRACT FROM AUTHOR]

A method is presented for analysing maternity history data to provide period estimates of parity progression ratios, birth intervals and related indices. This is applied to a sample of the marriage and maternity histories from the Census of England and Wales of 1971 and shows: (a) a general increase through the 1950s and into the 1960s in period estimates of marriage and parity progression ratios, especially in the progression from first to second birth; (b) a general acceleration of fertility with, again, the second birth interval becoming particularly short and compact; and (c) very steep declines in third and fourth birth progression ratios from the mid-1960s. Birth interval distributions altered during the period examined. Decomposition of a progression-based total fertility index shows change in the ratios for lower birth orders to have dominated the fertility upswing and declines in ratios for higher birth orders to have initiated the subsequent decline. [ABSTRACT FROM AUTHOR]

An analysis of data mainly from China's 1990 and 2000 censuses and 2005 mini-census shows how fertility decline between 1975 and 2005 in the province of Guangdong has been influenced by both fertility policy and economic and social development. Guangdong's development since 1975 has been very rapid and has attracted huge numbers of migrants from other provinces. The analysis of the province's fertility trend from 1975 shows clearly the influence of fertility policy on the trend. The analysis also shows that economic development has brought about large changes in population composition by urban/rural residence, education, occupation, and migration status, which, together with large fertility differentials by these characteristics, have contributed substantially to Guangdong's fertility decline, in large part through changes in proportions currently married. [ABSTRACT FROM AUTHOR]

Poland experienced a rapid fertility decline after the end of the socialist regime in 1989. At the same time, it became much more difficult, especially for women, to act on their determination to find and keep paid employment. To investigate whether women postponed childbearing until they found a job, we undertook a simultaneous estimation of transitions to childbirth and entry to and exit from employment. The results reveal a strong incompatibility between childbearing and employment, but also that employment does not function as a barrier to childbearing but rather that it is an important precursor when women plan how to reconcile their intentions to work and to have children. We conclude that better prospects for women's employment could result in increased fertility. [ABSTRACT FROM AUTHOR]

Before the demographic transition in Thailand, fertility was high, but not uniformly so. As in other pre-transition settings, Thai fertility responded to pressures and opportunities created by socioeconomic structure and land availability. Drawing upon provincial data from the 1947 and 1960 censuses of Thailand, we find a strong 'frontier effect' on Thai fertility in the 1950s. Fertility was higher in sparsely settled frontier provinces and lower in provinces with higher population density relative to cultivatable land. This finding is robust and holds up with controls for agricultural employment, land quality, and the sex ratio (an indicator of sex-selective migration). The effect of population pressure lowers the likelihood of marriage and of marital fertility. The findings from Thailand are consistent with the research of Easterlin on the nineteenth century United States and with other pre-transition societies. We suggest how demographic transition theory might be broadened to include fertility dynamics in pre-transition societies. [ABSTRACT FROM AUTHOR]

Does a woman's reproductive history influence her life span? This study explores the question with data from the contemporary female populations of England and Wales and Austria. It is the first comparative study to investigate the relationship between fertility and mortality late in life. We find similar patterns and age-specific trends of excess mortality in both populations: parity significantly influences longevity, as do both an early and a late birth. These differences in longevity are not explained by differences in educational or family status. The impact of a woman's reproductive history on her life span is small, however, compared to the influence of her level of education or family status. [ABSTRACT FROM AUTHOR]

A method of partitioning the fertility impact of infant and child death into two components - a physiological and a behavioural effect - is proposed by use of the Cox hazard model with three dummy variables that indicate the time of child death and the status of breastfeeding with reference to the return of menstruation postpartum. An application of the method to the 1991 Bangladesh Contraceptive Prevalence Survey data suggests that the effect from the physiological mechanism outweighed the effect from the behaviourial mechanism (the former effect raising the hazard of an additional birth by nearly 90 per cent). It appears that the effect of a child death declined over time and an early cessation of breastfeeding was not the sole cause for invoking the physiological mechanism. The risk of childbirth rose sharply among the educated if their children died, although the main effect of education itself was to reduce the risk. [ABSTRACT FROM AUTHOR]

This study uses data from the 1990 Census of China for Xinjiang Uighur Autonomous Region to examine phenomena that, to date, have been examined primarily at the national level: fertility and sex ratios at birth of women who already have at least one surviving child. Comparing data for Uighurs, Kazakhs, Hui, and Han, it finds enormous differences in fertility between the nationalities in the presence of high levels of fertility control. Also, for all four nationalities the extent of fertility control is dependent on the sex of surviving children. Women who had no previous sons, or who had many daughters, were likely to continue to try to have children even at ages and parities past which they would normally have stopped childbearing. Finally, disproportionately feminine sex ratios at birth are found for couples who have had several sons and no daughters. Hence, researchers interested in the question of unusual sex ratios at birth in China need to account for `missing boys' as well as `missing girls' [ABSTRACT FROM AUTHOR]

Data from the World Fertility Survey and the Demographic and Health Survey are used to analyze differences in infertility in Cameroon and Nigeria. It was assumed that specific patterns of behaviour are associated with higher infertility and that women's lives are greatly affected by their ability to reproduce. Both hypotheses are supported by multivariate analysis. Odds of being infertile were significantly higher for women who became sexually active in their teens, and those of having been married several times or of being currently unmarried are higher for infertile women. The patterns of infertility vary substantially within both Cameroon and Nigeria, but are very similar in the two countries. The most striking difference is that the incidence of infertility became less variable during the 1980s between different groups in Cameroon, but more diverse in Nigeria. Differences in the latter country are also more age-dependent than in the former. [ABSTRACT FROM AUTHOR]

Attempts to demonstrate the dependence of fertility decline in the Third World on radical change have often depended on simplistic statistical analyses. Here some of the data used to explore the relationship between fertility, and land size and ownership, are re-examined. It is concluded that the land-fertility hypotheses of Stokes and Schutjer are not supported by the evidence, but that such analyses are inherently inconclusive and ambiguous. Instead, an understanding of the wider institutional context is called for. The Population Establishment - foreign and international donors supporting population programmes and research - recruits an intelligentsia to validate its activities. The philosophy of this intelligentsia is examined and rejected through an analysis of ideas it derives from the World Fertility Survey and the Matlab family planning project. It is concluded that the Establishment perpetuates rapid population growth by legitimizing unpopular and elitist governments, and by misleading them to believe that fertility decline can, indeed, occur in a political economy of inequality and injustice. [ABSTRACT FROM AUTHOR]

The article focuses on a study, which discusses several issues related to interaction of middle-aged Japanese with their parents. According to authors, their analysis has shown that both socio-economic and demographic factors affect the probability of middle-aged Japanese men living with their parents, while only demographic factors appear to influence the co-residence of women with their parents at this time. Further declines in fertility and mortality may have opposite effects on the probability of co-residence, as modeled in this article, but future socio-economic change may reduce the probability of men living with parents. Contact with non-co-resident parents is affected by distance in most cases. Socio-economic variables have few effects. For women, being the eldest child increases frequency of contact, and for both sexes, telephone calls are made more frequently when parents are living alone or with a spouse only. More research on the emotional and financial aspects of intergenerational interaction in Japan is needed both within and across household boundaries. Critical to such work will be socio-economic and demographic information on all the parties potentially involved, both young and old, and data on how interactions change over the course of the life cycle.

China's one-per-hundred population survey, conducted in mid-1987, provides the first nation-level data with which to study recent fertility change in China. Using a recently developed extension of the own-children' method of fertility estimation, period parity progression ratios are computed from the survey data. Comparison with similar statistics computed from the 1982 one-per-thousand fertility survey provides a rigorous check on the quality of the results. The level of fertility so measured rose by 13 per cent between 1985 and 1987, compared with an increase of eight per cent in conventional total fertility ratios. Nearly 90 per cent of the increase was due to rising levels of progression from first to second birth. There can be little doubt that this, in turn, was due to a relaxation in the one-child family policy. Overall levels of progression to births of higher orders have been declining since 1982, but the evidence suggests that this is so only because of stringent government efforts to control births of third and higher orders. [ABSTRACT FROM AUTHOR]

Data from the Thailand Demographic and Health Survey permit a detailed examination of the pattern of contraceptive initiation in terms both of first post-marital contraceptive use and initiation of use following childbirth. A clear trend towards beginning contraception earlier in the family-building process over the course of the fertility transition is evident. During the earliest stage, contraception was first used mainly after a couple had already achieved their desired family size, but later on couples increasingly began use in order to space births, and most recently it has become common to begin use to delay the start of childbearing. There are two distinctive patterns of contraceptive initiation following childbirth. For women who chose sterilization, initiation occurs during the immediate post partum period, while for those who used other methods, use most commonly began shortly after the return of menses. As a result, few Thai women are at present unprotected against unplanned pregnancies for any substantial period of risk following childbirth. Beginning to use contraception early in the family-building process and rapid adoption of contraception following childbirth are now found in most segments of Thai society, testifying to the maturing of Tailand's fertility transition. [ABSTRACT FROM AUTHOR]

The decline of fertility in Czechoslovakia on the territory of the Czech Socialist Republic began with a rise in the age at marriage; the decline of marital fertility began only after 1860. On the territory of the Slovak Socialist Republic marital fertility began to decline after 1900 without previous significant changes in the age at marriage. The differences between the demographic behaviour in the two parts of Czechoslovakia have persisted, although they are now gradually disappearing. There are other significant regional differences in the fertility decline caused by the overall process of economic and social development. The end of the demographic transition in the Czech Socialist Republic came during the 1930's and in the Slovak Socialist Republic during the 1960's, [ABSTRACT FROM AUTHOR]

The article focuses on the sensitivity of estimated fertility levels and trends to alternative interpretations of responses in fertility surveys. It uses data from the 1975 Bangladesh Fertility Survey. It presents some simple mathematical models to evaluate the consequences of an erroneous interpretation. The author also presents some guidelines for a correct interpretation. It refers to a package program of the Central Office of the World Fertility Survey which edits and imputes different types of dates in World Fertility Survey questionnaires. It is found that in Bangladesh, the imputation had no serious impact upon, fertility levels.

The duration of the post-partum non-susceptible period is a major determinant of birth intervals in populations with relatively low levels of contraception. Since it depends largely on the length of breast-feeding, it may change rapidly with socio-economic development. A system of model schedules that summarize the underlying regularities found in empirical schedules is proposed. With a logit transformation, observed schedules of breast-feeding can be related to a standard breast-feeding schedule by just two parameters. Similarly, observed schedules of post-partum amenorrhea can be related to standard amenorrhea schedule. The two systems provide a means of obtaining relatively robust estimates of the duration of lactation or amenorrhea from partial and flawed data. Several applications of the models for estimation problems, for simulation purposes and for the analysis of the relationships between breast-feeding, amenorrhea and post-partum abstinence are discussed.

The computer simulation model, REPSLM-B is used to study the random errors in selected cohort natality measures. A brief overview of various analytic approaches for studying such random errors is first presented. Results from analytic models are then compared with those obtained from the computer simulation model. The natality measures studied are age-specific rates, total fertility, births per person-years lived and cumulative birth rates. Also considered are selected indices of birth intervals, mean age at childbearing and the infant mortality rate. In most instances, the use of conventional binomial type models underestimated the random variation of the fertility indices. Among the conventional fertility measures, total fertility, births per person-year lived, and the cumulative birth rates at older ages were found to be the least variable. While life-table means and medians were observed to be less variable than observed mean birth intervals, the life-table medians of birth intervals were the least variable. [ABSTRACT FROM AUTHOR]