The End of the Fertility Transition in the Developed World

By the late 1990s the average period total fertility rate in the developed world had declined to 1.6, a level substantially lower than projected in the 1970s and 1980s. This article examines recent trends and patterns in fertility in the developed world with particular emphasis on the effects and implications of changes in the timing of childbearing. The main objective is to demonstrate that while fertility in these countries is indeed low, women's childbearing levels are not as low as period measures such as the total fertility rate suggest. To obtain a full understanding of the various dimensions of fertility change. several indicators are examined, including period and cohort fertility by birth order and childbearing preferences. An analysis of these indicators demonstrates that period fertility measures in many developed countries are temporarily depressed by a rise in the mean age at childbearing. The distortion of the TFR is as great as 0.4 births per woman in Italy and Spain. These effects have been present in many developed countries since the 1970s and could continue for years into the future. But tempo effects are temporary, and once the postponement of childbearing ends—as it eventually must—the corresponding fertility‐depressing effect stops, thus putting upward pressure on period fertility. Countries with very low fertility and substantial tempo effects may well experience rises in fertility in the near future if the timing of childbearing stabilizes. Even if this happens, however, it seems unlikely that fertility will rebound to the replacement level.     

生育进度效应调整指标研究的新进展

随着经济和社会的不断发展,生育推迟现象在全世界范围内日益普遍。由于生育推迟所产生的进度效应会对生育水平造成影响,因此,如何测度生育进度效应便成了人口学界研究的重要内容。自Bongaarts和Feeney的去进度效应总和生育率提出以来,各种新的改进方法与指标不断出现。本文对生育进度效应调整指标的新进展及具体指标进行梳理与比较。从时期角度出发,主要包括方差效应调整后的TFR、PATFR*、调整后的TFRSUV_N和ITFR四种指标;从队列角度出发,主要包括TFRp*、TFR†和ACF三种指标,这些指标有各自的优缺点。研究发现:首先,由于不同去进度效应改进指标的假设、适用条件、研究角度、改进方向都不同,很难有一套数据同时适用于多种去进度方法,因此,生育进度效应的诸多改进指标并没有哪个指标“更好”,只有“更合适”;其次,绝对的去进度效应只能停留在理论层面,而实际上却很难做到,种种去进度方法都只是一种“相对的去”,而不是“绝对的去”。过去我们所熟悉的进度效应是生育推迟,而目前世界范围内生育推迟速度开始逐渐放缓,未来我们甚至不能排除生育推迟在某个时期或某些区域会发生逆转,届时可能会出现与目前影响方向相反的进度效应,这可能是下一步关于生育进度效应研究应该注意的新方向。     

Multivariate analysis of parity progression—based measures of the total fertility rate and its components

This article describes a methodology for applying a discrete-time survival model—the complementary log-log model—to estimate effects of socioeconomic variables on (1) the total fertility rate and its components and (2) trends in the total fertility rate and its components. For the methodology to be applicable, the total fertility rate (TFR) must be calculated from parity progression ratios (PPRs). The components of the TFR are PPRs, the total marital fertility rate (TMFR), and the TFR itself as measures of the quantum of fertility, and mean and median ages at first marriage and mean and median closed birth intervals by birth order as measures of the tempo or timing of fertility. The focus is on effects of predictor variables on these measures rather than on coefficients, which are often difficult to interpret in the complex models that are considered. The methodology is applicable to both period and cohort data. It is illustrated by application to data from the 1993, 1998, and 2003 Demographic and Health Surveys (DHS) in the Philippines.     

Birth delays skew developing world's fertility figures

This article explains that birth delays skew developing world's fertility figures. When successive groups of women who have delayed childbearing start having children, the rapid fertility decline stalls. Such change in the timing of childbearing skews the total fertility rate (TFR). Analysis of the tempo component of TFR trends in Taiwan suggests that tempo effects reduced its TFR by about 10% in the late 1970s and early 1990s and by about 19% in the late 1980s. In Colombia, on the basis of increasing mean maternal age at childbirth between the 1970s and the late 1980s, tempo distortions of the TFR during the most of the 1980s seem likely. Moreover, many developing countries are now experiencing rapid fertility declines that are in part attributable to tempo changes. These changes have accelerated past fertility transitions, but they also make these countries vulnerable to future stalls in fertility when the delays in childbearing end. Since fertility reductions caused by tempo effects lead to real declines in birth rates and hence in population growth, countries that wish to reduce birth rates can take actions that encourage women to delay marriage and the onset of childbearing.     

Timing effects on first marriage: twentieth-century experience in England and Wales and the USA

Recent substantial declines in first marriage in Western countries have been accompanied by increases in the average age at first marriage. Since the period proportion ever marrying, PEM, is sensitive to cohort tempo changes, the recent fall in the PEM may simply reflect cohort delays in marriage. The importance of timing factors is examined in the light of twentieth-century experience of first marriage in England and Wales and the USA. Using a variant of the Timing Index developed in research on fertility, we measure cohort timing effects for marriage and calculate an adjusted PEM. After examining twentieth-century trends in nuptiality for men and women, we find substantial tempo effects on the period PEM. Adjusted PEM values show a real decline in marriage for cohorts, but that decline is considerably smaller than the one shown by the unadjusted figures. This is especially true for England and Wales, where the decline in marriage was much greater.     

Low fertility due to delay in -- not dearth of -- births

Population Council demographer John Bongaarts and his colleague Griffith Feeney argue that recent concern about a lack of births overlooks the fact that many women in developed countries are simply choosing to bear children later than women used to. So-called birth dearths are often caused by temporary delays in childbearing. The two demographers have designed a new way for demographers to account for the timing, or tempo, of childbearing in estimates of fertility. Their tempo-adjusted total fertility rate (TFR) allows demographers to correct skewed fertility trends, such as those leading to projections of birth dearths. The new measure provides a better indication of women's true propensity to bear children. Standard measures of fertility are distorted by changes in tempo. Such changes occur when large numbers of couples delay or accelerate their initiation of family building. The authors used historical data and theoretical arguments to validate the tempo-adjusted TFR, which improves upon the two common measures of fertility. Flaws in the TFR and the completed fertility rate (CFR) are corrected by Bongaarts and Feeney's new measure. To demonstrate their new tool, they examined the below-replacement fertility seen in recent decades in the US. By the mid-1990s, the TFR in almost every developed country had fallen below the replacement level of 2.1 births/woman, and in Italy, Spain, and Germany it fell below 1.5. If such fertility persists, declining population size, extreme population aging, and financial pressure upon social security systems may result. However, if fertility preferences hold at current levels, the very low fertility rates observed in the developed world will approach 2 children/couple.     

A demographic explanation for the recent rise in European fertility

Between 1998 and 2008 European countries experienced the first continent-wide increase in the period total fertility rate (TFR) since the 1960s. After discussing period and cohort influences on fertility trends, we examine the role of tempo distortions of period fertility and different methods for removing them. We highlight the usefulness of a new indicator: the tempo- and parity-adjusted total fertility rate (TFRp*). This variant of the adjusted total fertility rate proposed by Bongaarts and Feeney also controls for the parity composition of the female population and provides more stable values than the indicators proposed in the past. Finally, we estimate levels and trends in tempo and parity distribution distortions in selected countries in Europe. Our analysis of period and cohort fertility indicators in the Czech Republic, Netherlands, Spain, and Sweden shows that the new adjusted measure gives a remarkable fit with the completed fertility of women in prime childbearing years in a given period, which suggests that it provides an accurate adjustment for tempo and parity composition distortions. Using an expanded dataset for ten countries, we demonstrate that adjusted fertility as measured by TFRp* remained nearly stable since the late 1990s. This finding implies that the recent upturns in the period TFR in Europe are largely explained by a decline in the pace of fertility postponement. Other tempo-adjusted fertility indicators have not indicated such a large role for the diminishing tempo effect in these TFR upturns. As countries proceed through their postponement transitions, tempo effects will decline further and eventually disappear, thus putting continued upward pressure on period fertility. However, such an upward trend may be obscured for a few years by the effects of economic recession.     

China's Below‐Replacement Fertility: Recent Trends and Future Prospects

Between 1970 and 1990, China experiencoed a rapid and sharp fertility decline—from total fertility rates of approximately six births to two. The degree to which Chinese fertility has continued to fall after 1990 is controversial. We use survey data from the 1997 National Population and Reproductive Health Survey and from the 2001 Reproductive Health and Family Planning Survey to document recent trends in Chinese fertility. Our estimates provide further evidence that China's fertility is well below‐replacement level at the turn of the twenty‐first century—with TFR levels of approximately 1.5 children per woman. Trends in parity‐specific cohort fertility by age also suggest below replacement completed fertility for cohorts still in the childbearing years. In the article's second section, we identify key components of low period fertility in order to frame our discussion of two questions: 1) in what ways is Chinese low fertility different from/similar to that in other low‐fertility countries? And 2) what are the likely future trends in Chinese fertility?     

A sensitivity analysis of the bongaarts-feeney method for adjusting bias in observed period total fertility rates

Our sensitivity analysis shows that the adjusted TFR'(t) using the formula of Bongaarts and Feeney (1998), which assumes an invariant shape for the fertility schedule, usually does not differ significantly from an adjusted TFR"(t) that allows the shape of the fertility schedule to change at a constant annual rate. Because annual changes in the shape of the fertility schedules often are approximately constant except in abnormal conditions, the Bongaarts-Feeney (B-F) method is generally robust for producing reasonable estimates of the adjusted TFR'(t). The adjusted TFR'(t) neither represents any real cohort experiences from the past nor forecasts any future trend. It merely provides an improved reading of the period fertility measure, which reduces the tempo distortion.     

Cohort disaggregation analysis of fertility data from a sample survey

Social differentials in cumulative fertility revealed by field surveys in a number of countries typically have been interpreted with the implicit assumption that the timing of childbearing within the reproductive period remains constant. However, the reproductive histories that have been collected in such surveys provide a largely unexploited source of data for the analysis of trends in timing. An analysis by birth cohort of the fertility experience of 592 ever-married women surveyed in San Juan, Puerto Rico, in 1966 shows that significant changes in timing have occurred. Women in the more recent birth cohorts are distinguished by earlier childbearing and sustained higher fertility in consecutive age periods. The inter-cohort differences remain when adjustments are made for duration of time in legal and consensual unions.     

Tempo and the TFR

Tempo effects in period fertility indicators are widely regarded as a source of bias or distortion. But is this always the case? Whether tempo change results in bias depends, in the view advanced here, on the measure used, the meaning of bias/distortion, and the objective of analysis. Two ways of construing bias in period measures are suggested, and their relevance is discussed in the context of five broad purposes for measuring period fertility: describing and explaining fertility time trends, anticipating future prospects, providing input parameters for formal models, and communicating with nonspecialist audiences. Genuine timing effects are not biasing when period fertility is the explanandum but are distorting when the aim is to estimate cohort fertility. Alternatives to tempo adjustment are available that are a more defensible solution to the issue of timing change. Tempo adjustment could be more fruitfully considered a form of modeling rather than empirical measurement. The measurement of period fertility could be improved by relying more on a statistical approach and less on indicators based on stable assumptions. Future progress will depend on integrating research on measurement with substantive investigation.     

Has East Germany Overtaken West Germany? Recent Trends in Order‐Specific Fertility

Some 20 years after reunification, the contrast between East and West Germany offers a natural experiment for studying the degree of persistence of Communist-era family patterns, the effects of economic change, and fertility postponement. After reunification, period fertility rates plummeted in the former East Germany to record low levels. Since the mid-1990s, however, period fertility rates have been rising in East Germany, in contrast to the nearly constant rates seen in the West. By 2008, the TFR of East Germany had overtaken that of the West. We explore why fertility in East Germany is higher than in West Germany, despite unfavorable economic circumstances in the East. We address this and related questions by (a) presenting an account of the persisting East/West differences in attitudes toward and constraints on childbearing, (b) conducting an order-specific fertility analysis of recent fertility trends, and (c) projecting completed fertility for the recent East and west German cohorts. In addition to using the Human Fertility Database, perinatal statistics allow us to calculate a tempo-corrected TFR for East and West Germany.     

Fertility transition in Arab countries: A re-evaluation

During the two decades extending from the late 1970s, average TFR in Arab countries declined by more than two births per woman. The paper examines changes in the proximate determinants of Arab fertility and evaluates some of the underlying factors that are variously held to have influenced the fertility transition. The proximate and underlying determinants of fertility in Arab countries are compared with those of other regions. Among the factors examined are economic hardship, delayed marriage, and female education and labour force participation. The roles of oil revenues and of the Islamic religion are also considered. An interesting feature is that fertility declined despite continued desires for large families.     

On the tempo of childbearing in England and Wales

Abstract The paper describes a computerized model developed to simulate the fertility of a hypothetical marriage cohort in a closed population. The model was applied to England and Wales fertility data of marriage cohorts of the years 1951 to 1970. For each of these cohorts, the computer was programmed to construct five series of tables showing birth-order probabilities, family size frequency distribution, mean length of intervals between marriage and successive births, parity progression ratios and mean family sizes of fertile women. The results showed that the fertility of the cohorts of women who married between the middle 1950s and the early 1960s was character ized by a declining trend in the frequency of childlessness and by a dramatic increase in the proportion of marriages with two or more children. Since 1964 or so, there has been a downward trend in duration-specific birth-order probabilities. The analysis suggests that the recent drop in fertility may well prove to be the effect of an upward shift in the timing of births as well as a fall in completed fertility.     

浅析中国1991～2000年生育模式变化对生育水平的影响

分析生育模式的变化对生育水平的影响 ,通过计算 1 991～ 2 0 0 0年中国去进度效应总和生育率TFR’ ,清楚地看出 ,提高初婚年龄和拉大一孩至二孩生育间隔所造成的生育模式的变化导致中国 1 0年间TFR偏低。去进度效应总和生育率TFR’较之TFR更加接近中国妇女的实际终身生育水平     

A fertility analysis of New Zealand marriage cohorts

New Zealand annual returns of non-Maori live legitimate births 1913 to 1955 were tabulated longitudinally by marriage duration and birth order. The figures were used as numerators of fertility rates of forty marriage cohorts, specific for duration and birth order ; the twenty-four oldest cohorts had virtually completed fertility. For the denominators of the rates, the cohorts of initial size (estimated by a method similar to that described by P. H. Karmel) were survived by observing changes over time through divorce, death, widowhood, war-widowhood, and net external migration. The aim was to provide a set of data of the best possible approximation on variations of cohort fertility.

Total cohort rates, cumulated for twenty years’ duration of marriage, and segmental rates of relevant sub-periods are given for parities o to 7+. Total rates of the cohorts of completed fertility yielded values of family size, and were also used for parity progression ratios (by L. Henry’s formula). Segmental rates permitted a study of changes in timing maternities.

The analysis, which needs as a corollary a nuptiality analysis, is concerned, so far with past experience. It confirms the decline in number and proportion of large families. Both the parity progression ratios, and segmental rates of cohorts of as yet incomplete fertility, suggest some recent recovery in three- and fourchild families. For total fertility, such recovery might even be more significant than the observed decline in large families. On the other hand, birth-order specific changes in timing suggest lengthening of intervals among older cohorts as a trend upon which is superimposed the fluctuation due to postponement of, and recovery of a portion of postponed maternities. A construction of hypothetical timing patterns for incomplete cohorts by a simplified method of projection does not lead very far without support of observations on spacing that differentiate for family size.     

An Explanatory Model for Projecting Regional Fertility Differences in the Netherlands

Current differences in the level of the total fertility rate (TFR) between Dutch municipalities are smaller than they were in the 1970s and 1980s. Nevertheless, there are still considerable differences. Small municipalities have higher TFRs than large cities. This article aims to answer the question whether these differences will decline further until differences between large and small cities disappear. For that purpose we develop a regression model of regional differences in the TFR including demographic, socioeconomic, and cultural variables. Using the estimation results we decompose differences in fertility between large and small cities into the contribution of differences in levels of the determinants versus differences in the relationships between the determinants and fertility. The results show that differences in cultural variables have a larger effect on differences in the TFR than the demographic and socioeconomic variables. As cultural differences do not tend to change quickly, they will not lead to quick changes in regional differences in the TFR. Demographic differences are not expected to lead to strong changes either, as the two demographic variables (household structure and ethnic structure) have opposite effects. As the effect of the socioeconomic variable is caused by differences in the magnitude of the regression coefficient rather than by differences in the value of this variable, even if differences in this variable disappeared, this would still not lead to convergence of the TFR. Thus the article concludes that differences in the TFR between large and small cities are not likely to diminish quickly.     

New Cohort Fertility Forecasts for the Developed World: Rises,Falls, and Reversals

With period fertility having risen in many low‐fertility countries, an important emerging question is whether cohort fertility trends are also reversing. We produce new estimates of cohort fertility for 37 developed countries using a new, simple method that avoids the underestimation typical of previous approaches. Consistent with the idea that timing changes were largely responsible for the last decades' low period fertility, we find that family size has remained considerably higher than the period rates of 1.5 in many “low‐fertility” countries, averaging about 1.8 children. Our forecasts suggest that the long‐term decline in cohort fertility is flattening or reversing in many world regions previously characterized by low fertility. We document the marked increase of cohort fertility in the English‐speaking world and in Scandinavia; signs of an upward reversal in many low‐fertility countries, including Japan and Germany; and continued declines in countries such as Taiwan and Portugal. We include in our forecasts estimates of statistical uncertainty and the possible effects of the recent economic recession.     

Evolving Fertility Goals and Behaviors in Current U.S. Childbearing Cohorts

In the post-Recession era, U.S. fertility rates have continued to fall. It is unclear if these declines are driven by shifts in fertility goals or growing difficulty in achieving goals. In this paper, we construct synthetic cohorts of men and women to examine both cross-cohort and within-cohort changes in fertility goals using multiple cycles of the National Survey of Family Growth. Although more recent cohorts exhibit lower achieved fertility at younger ages than earlier cohorts at the same age, intended parity remains around two children, and intentions to remain childless rarely exceed 15 percent. There is weak evidence of a growing fertility gap in the early 30s, suggesting more recent cohorts will need considerable childbearing in the 30s and early 40s to “catch up” to earlier goals, yet low-parity women in their early 40s are decreasingly likely to have unfulfilled fertility desires or intentions to have children. Low-parity men in their early 40s, though, are increasingly likely to intend children. Declines in U.S. fertility thus seem to be largely driven not by changes in early-life fertility goals so much as either a decreasing likelihood of achieving earlier goals or, perhaps, shifts in the preferred timing of fertility that depress period measures.     

Japan's fertility: effects of contraception and induced abortion after World War II

This report studies the effects of contraception and abortion on crude birth rate (CBR) and total fertility rate (TFR) in Japan from 1947-1980. The CBR declined from 34.3 in 1947 to 17.3 in 1957, and the TFR from 4.5 to 2.0 in the same period. Both stabilized (CBR in the range of 17.0 to 19.0 and TFR at 2.0 to 2.1) between 1957 and 1973. This dramatic decline in fertility was initiated under the serious socioeconomic difficulties of post-World War II Japan. At the onset of the postwar fertility decline, fertility within marriage was controlled most strongly by induced abortion, and to a lesser extent, lactation and contraception. During the period of stable low fertility (1960-1980) the effect of abortion decreased and the effect of contraception increased. KAP surveys show that in the late 1970's more than 75% of contraceptive users in Japan employed the condom, while condom use in other Asian countries is generally very low. A shift from traditional to modern methods of contraception is unlikely to alter the already low level of fertility in Japan but would have considerable social, medical, and economic impact.