The conflicting effects of delayed marriage and declining divorce rates on cumulative fertility in Indonesia

The impact of nuptiality patterns on fertility in Indonesia is examined with multivariate analysis controlling for 8 socioeconomic variables. Data were obtained from the 1987 Indonesian Contraceptive Prevalence Survey. Marriage is usually universal by age 35, and in this study all women 30 years had been married at least once. 20% were married at 15 years and 45% married at 18 years. For those married more than once, prevalence of 1st marriage was 7% for women 15-24 years, 15% for 25-34 years, and 29% for 35-49 years. In 1976 and 1987, the age at 1st marriage and number of times married were both strongly and negatively correlated. The % never marrying between 15-49 years rose from 21.5% to 26.4% between 1980-87. Cumulative fertility w as related to both age at 1st marriage and number of times married. Muslim women, women in Java and Bali, and rural women all marry at younger ages. 27% of the variance in age at 1st marriage is explained by women aged 25-34, current residence, region, religion, language, education, and work or not before marriage. The number of times married is also associated with socioeconomic characteristics without control, i.e., Muslim women 25-34 years were 3 times more likely to have been married more than once than in other faiths. With controls for socioeconomic factors, only 13% of the variance is explained and being Muslim has no statistically significant effect. The important net effects were being interviewed in Balinese, age, and age at 1st marriage. In the analysis of cumulative fertility, age at 1st marriage consistently is related to cumulative fertility in almost every socioeconomic group when age and number of times married is controlled for. Women married more than once have lower fertility. 36% of the variance is explained by all the variables. Being married more than once leads to having 2.1 fewer children. A 5-year delay in marriage leads to .75-1.1 fewer children. When other variables are controlled for, neither educational level nor prior work experience has a statistically significant effect on cumulative fertility. In the contraception analysis, women married more than once used contraception less. Among women 35-49, those marrying later had higher contraceptive use, but in general contraceptive use declined with age. More information is needed on why marriage patterns are changing.     

An analysis of the change of marriage pattern of Beijing women]

Changes in marriage patterns occur primarily in changes in the age at marriage. During a study of fertility among Beijing, China, women in 1981, another study was undertaken of the marriage situation of 8299 women who were born in 1914, 1920, 1930, 1940, and 1946. Data show that the rate of unmarried women was close to zero, which is one reason for the high birth rate in the past. A majority of the urban and rural women born in 1914, 1920, and 1930 married before the age of 15 years, indicating that the economic, social, and marriage customs for those decades changed very little. The 1940 cohort, however, showed no urban marriages prior to the age of 15 years and less than 1% in the villages, the reason being that these women were of marriageable age in the mid-to-late 1950s when China underwent major social and economic changes that raised the status of women and permitted them to join the work force or go to school. Very few urban women in the 1946 cohort married before 20 years of age, and the number of rural women who married before they were 18 years old declined noticeably. Findings also show that for both urban and rural women, the average age at marriage was 1-3 years later than the modal age at marriage. Beginning with the 1940 cohort the age at marriage was older by 2 1/2 years, signaling major changes. Except for the 1914 cohort, the median age at marriage for all others gradually became higher. 70% of the 1946 cohort voluntarily married after turning 23 years old, reflecting the effectiveness of the late marriage, late birth policy. Although close to 59% of rural women born in 1946 married before 23 years of age, nearly double the rate for urban women, it is nevertheless a major change from the 1930 cohort where 95% of the women married before turning 23 years old.     

Age at marriage is rising for Asian women and men,according to new data

The social transformations in Asia are described: delayed age at marriage and the proportions marrying. Policy implications are ascertained. The norm for female age at marriage has risen from 15 years to 17-18 years in south Asia, and from 18 years to 24 years and older in east Asia. Men's marriage age has also risen but not as much. Concurrent changes have occurred with fertility declines and small family sizes and lower population growth, with changing roles for women, and with emergent youth subcultures and increased prevalence of premarital sexual behavior. The number of singles is rising and expected to continue to rise. Examples are given of marriage age changes for Nepal and Bangladesh, Sri Lanka, Malaysia, South Korea, and regional totals. Southeast Asian countries experienced less dramatic changes, and changes primarily in the 20-24 year old group (from 30% to 74% of single women). Change for men has been less regular and with less magnitude. In Southeast Asia, the rise in marriage age for men has risen only 1-2 years compared with women. East Asia patterns vary by country, i.e., South Korean increases of 6 years, Taiwanese increases of 4 years, and 2 years in Japan. Single males have been common in South and Southeast Asia, while in East Asia married male teens 25 years are rare. Marriage timing for men is not as closely associated as for women with social and cultural change. Downturns for men follow momentous, temporary disruptions such as happen during wars and periods of migration, while women's patterns are more reflective of structural change. The trend for never marrying is on the increase, particularly for men in Japan (1.1% in the 1920s to 18% in the early 1980s for men 50 years). Women not ever marrying are increasing in Thailand, Bangladesh, and Hong Kong. Never marrying is common in urban or educated populations, i.e., Singapore, Thailand, and Philippines. The implications are a longer gap between successive generations and a shorter period of exposure to risk of conception. Research findings have shown that a 1 year delay in age at 1st marriage reduces fertility by 20% of a child. Schooling delays marriage age as well as marriage laws, but structural and economic changes may be more important than policy changes. Policies affect the status of women and opportunities.     

How female education affects reproductive behavior in urban Pakistan

Although Pakistan remains in a pretransitional stage (contraceptive prevalence of only 11.9% among married women in 1992), urban women with post-primary levels of education are spearheading the gradual move toward fertility transition. Data collected in the city of Karachi in 1987 were used to determine whether the inverse association between fertility and female education is attributable to child supply variables, demand factors, or fertility regulation costs. Karachi, with its high concentration of women with secondary educations employed in professional occupations, has a contraceptive prevalence rate of 31%. Among women married for less than 20 years, a 10-year increment in education predicts that a woman will average two-fifths of a child less than other women in the previous 5 years. Regression analysis identified 4 significant intervening variables in the education-fertility relationship: marriage duration, net family income, formal sector employment, and age at first marriage. Education appears to affect fertility because it promotes a later age at marriage and thus reduces life-time exposure to the risk of childbearing, induces women to marry men with higher incomes (a phenomenon that either reduces the cost of fertility regulation or the demand for children), leads women to become employed in the formal sector (leading to a reduction in the demand for children), and has other unspecified effects on women's values or opportunities that are captured by their birth cohort. When these intervening variables are held constant, women's attitude toward family planning loses its impact on fertility, as do women's domestic autonomy and their expectations of self-support in old age. These findings lend support to increased investments in female education in urban Pakistan as a means of limiting the childbearing of married women. Although it is not clear if investment in female education would have the same effect in rural Pakistan, such action is important from a human and economic development perspective.     

Preliminary inquiry into changes among women in mountainous regions with regard to marriage and birth]

Research objectives were in China study the changes in marriage, birth, and birth and birth control of mountain women in the last 43 years. The methodology used was random sampling. The sample was taken based on 1% of the agricultural population. The findings show that the unmarried rate of women is currently very low. Remarriage occurs because of the loss of a spouse rather than divorce. Early marriage occurs more frequently with mountain women since they have gradually strayed from the traditional belief of marrying only once. Within the last 40 years, the average age when one married has gradually increased. The percentage of early marriages has decreased and the percentage of late marriages has increased. Prior to 1975, the birth rate was high and now it has decreased. The decrease in the birth rate in 1960 was due to natural disasters; however, the current decreases in the birth rate are due to family planning. The major factors influencing marriage of mountain farmers and birth rate are traditional feudalistic influences, economic life, marriage laws, population policies, culture, and education. The survey was conducted from August 1982 to April 1983. There were 20,174 women ranging from the ages of 15-67 who participated. Findings show that the majority of the unmarried women are now under the age of 25. The percentage of 1st marriages under the legal age reached 2.89%. The average 1st marriage age of women in the 1940s was 19.03. Between 1980-1982 it was 22.30, an increase of 3.27 years since 1940. The percentage of 1st marriages under the age of 18 in the 1940s was 35.96%. It decreased to 2.28% in 1980. The rate of 1st marriages over the age of 23 before 1970 remained approximately 5%. It increased to 56.84% in the early 1980s. The traditional feudalistic influences have greatly affected marriage of mountain farmers. The ratio of more than 1 child per couple reached a rate of over 40%. The improvement of economic life also increased the aggregate birth rate. It reached 7 in the 1950s. With the emphasis no longer on marriage laws and population policies but on family planning, the early marriage rate decreased to below 15% from a previous rate of 40%.     

Young women’s transition to marriage

This paper examines determinants of timing of marriage for young women by modeling the transition from the single to the married state by age. This approach, combined with a large longitudinal data set, allows us to disaggregate the analysis into fine age groupings and to include situational and attitudinal factors in our model. We find that those characteristics of a young woman’s parental family that reflect the availability of parental resources tend to decrease the chances of a marriage during the early teens. Chances of marrying appear to decrease with increases in the availability and attractiveness of alternatives to the wife role and in the costs of assuming it. We discuss these results from the perspective of the societal and parental normative pressures which affect timing of marriage for young women.     

From Privilege to Prevalence: Contextual Effects of Women’s Schooling on African Marital Timing

In Africa and elsewhere, educated women tend to marry later than their less-educated peers. Beyond being an attribute of individual women, education is also an aggregate phenomenon: the social meaning of a woman’s educational attainment depends on the educational attainments of her age-mates. Using data from 30 countries and 246 birth cohorts across sub-Saharan Africa, we investigate the impact of educational context (the percentage of women in a country cohort who ever attended school) on the relationship between a woman’s educational attainment and her marital timing. In contexts where access to education is prevalent, the marital timing of uneducated and highly educated women is more similar than in contexts where attending school is limited to a privileged minority. This across-country convergence is driven by uneducated women marrying later in high-education contexts, especially through lower rates of very early marriages. However, within countries over time, the marital ages of women from different educational groups tend to diverge as educational access expands. This within-country divergence is most often driven by later marriage among highly educated women, although divergence in some countries is driven by earlier marriage among women who never attended school.     

Marital protection and marital selection: Evidence from a historical-prospective sample of American men

Whether marriage causes people to live longer or whether healthier people select into marriage is an open question. In this study I followed a sample of men from age 18 to first marriage and ultimately to death. Health in early adulthood was represented by height and weight around age 20. The probability of ever marrying and the conditional probability of marriage in a given time period were lower for smaller men and greater for larger men. Marriage significantly lowered mortality risk even after controlling for health in early adulthood. Thus I found support both for selection into marriage and for protective effects of marriage.     

中国女性初婚模式变动趋势研究

20世纪80年代以来我国女性的初婚模式发生了显著的变化。本文使用人口普查资料、全国1%人口抽样调查数据、人口变动情况抽样调查数据以及IPUMS数据,通过女性平均初婚年龄、曾婚比例、年龄别初婚概率、终身结婚期待率和预期单身寿命等指标探究我国女性自20世纪80年代以来的初婚模式变动情况。研究发现30多年来我国女性平均初婚年龄在波动中上升,到2017年女性平均初婚年龄已经达到25.60岁,而教育程度的提高会推迟女性进入婚姻的时间,接受过高等教育的女性平均初婚年龄明显高于未受过高等教育的女性;另外,通过对各教育程度平均初婚年龄标准化与分解看到随着时间的推移,教育对女性的平均初婚年龄影响作用增大;20-30岁年龄段女性婚姻推迟明显,曾婚比例不断降低,但女性终身未婚比例很低,其中受过高等教育的女性婚姻推迟现象最为明显,但其自身的结婚意愿并未降低,大部分女性只是推迟结婚时间,并不是不结婚。对净婚姻表各指标进行计算发现1982-2010年女性的年龄别初婚概率下降,尤其在20-30岁年龄段下降明显,初婚峰值年龄推迟,结婚年龄集中现象减弱。终身结婚期待率下降速度趋缓,随着女性初婚年龄的推迟,2010年27岁之后的终身结婚期待率要高于1990年与2000年,29-35岁女性的预期单身寿命也较前30年低,较大年龄未婚女性结婚等待时间缩短。     

The Gendered Double Standard of Aging in US Marriage Markets

Using data on marriages collected in most US states between 1970 and 1988, we show that the older men are when they marry, the more years senior to their brides they are, whether it is a first or higher‐order marriage. While older men with more education marry down in age slightly more than less educated older men, the pattern of men marrying further down if they marry later holds strongly for all education groups. We consider several possible explanations for the tendency of men to marry further down in age if they are older at marriage. While we have no direct measure of physical attractiveness, we argue that the most compelling interpretation is that men, more than women, evaluate potential spouses on the basis of appearance. Because the prevailing standard of beauty favors young women, the older men are when they marry, the less they find women their own age attractive relative to younger women, leading them to marry further down in age if they are older at marriage. The consequence for women of men's preference for youth is more often that they remain unmarried than that they end up married to much older or less educated men.     

Fertility survey in the rural area of Henan province]

The population of Henan Province is 72,850,000, 92% of whom live in villages. From July 12 to August 11, 1981, a fertility survey was taken of 20 communes and 31 work brigades in the counties of Fugou, Shancai, and Dengfeng, in which 38,168 people and 5700 fertility registration forms were studied. In 1980, 15% of the 3 counties' population were women aged 18-49, 80% of whom were married. The birth rate was 134.56/1000, of which the rate for married women was 172.36/1000. A random sampling from Shancai of 18-49 year old women showed an average of 2.3 children per couple. The factors influencing rural fertility are economic, social, ideological, and cultural. The economic system of distribution according to work has actually encouraged population growth because in rural areas where the standard of living is low larger families with more workers have greater incomes than smaller families with fewer workers. Early marriage and early births are encouraged under this system, as evidenced by findings in Fugou County. The survey also found that in the 3 counties, virtually everyone marries, women who work tend to work in the village close to home, high illiteracy is prevalent, and traditional attitudes of favoring males over females were all factors contributing to early and frequent births. In order to lower rural birth rates, rural economy should be developed, old attitudes and habits should be changed, and literacy should be increased.     

The achievements in family planning work in Rudong County as suggested by the data of the Fertility Survey]

A 15% random sampling from Rudong County was recently taken to survey fertility rates. 1153 primary units were chosen, which included 160,832 people. Among this group were 57,050 women aged 15-67 years. Topics surveyed included: marriage, birth, contraception, and population structure. Rudong County, among the earliest counties in China to begin the work of birth control, started in the 1960s with birth control education. The natural rate of population increase by the early 1970s had already fallen. From 1974 to 1982 the average rate of natural population growth was 3.8/1000. Reproduction has gone from a rising trend to a stabilized trend. The base of the population structure pyramid has shrunk; the number of youths aged from birth to 14 years has fallen from 35.05% in 1964 to 21.77% in 1982. The number of people who must be supported (the old and the young) has decreased, lessening society's responsibility for them. 29.45% of the total population are over 65 years or under 14. Society's coefficient factor of support has fallen from 66.31% in 1964 to 41.75%. There is a decrease in the number of people marrying at a young age; the trend is toward marriage at a later age. The average age at marriage had risen from 23.81 years in 1980 to 23.89 years in 1981. The fertility rate has decreased, as has the number of offspring per woman. 1 child family is on the rise and multiple children family is on the decline. In 1981 the 1 child rate reached 92.98%, the 2 children rate was 6.63% and the multiple children rate was 0.49%. Prior to 1979 the 1 child rate was under 10%. The fertility rate fell from 136/1000 in the 1960s to 41.5/1000 in 1981.     

Schooling,marriage, and age at first birth in Madagascar

The low school attainment, early marriage, and low age at first birth of females are major policy concerns in less developed countries. This study jointly estimated the determinants of educational attainment, marriage age, and age at first birth among females aged 12–25 in Madagascar, explicitly accounting for the endogeneities that arose from modelling these related outcomes simultaneously. An additional year of schooling results in a delay to marriage of 1.5?years and marrying 1?year later delays age at first birth by 0.5?years. Parents’ education and wealth also have important effects on schooling, marriage, and age at first birth, with a woman's first birth being delayed by 0.75?years if her mother had 4 additional years of schooling. Overall, our results provide rigorous evidence for the critical role of education—both individual women's own and that of their parents—in delaying the marriage and fertility of young women.     

The cocos-keeling islands: A demographic laboratory

The Cocos Islands, which are situated in the Indian Ocean approximately halfway between Colombo and Fremantle, were first peopled early in the nineteenth century and were gradually developed as a very isolated coconut plantation with a labour force consisting partly of persons of Malay stock descended from the original group of settlers and partly of Bantamese contract labourers from Java. As the Cocos-born population increased in size, the dependence on contract labour decreased and, before the end of the century, all immigration ceased. The 1947 Malay population of the islands was about 1,800.

The islands are fascinating from a demographer's point of view because there was a virtually complete registration of live births, deaths and marriages and a partial registration of stillbirths. With these registration records it was possible to construct the life history of every individual from birth, through infancy and childhood to marriage, and thence through fatherhood or motherhood to death.

The picture revealed by an analysis of these records is that of a population with very high fertility and with mortality at a high level before the first World war and at a medium level after that war. Crude birth rates varied between 50 and 60 per thousand population during the period 1888 to 1947. Crude death rates were between 30 and 40 per thousand population until 1912 but under 2.0 per thousand population after 1918.

Most Cocos girls married before reaching the age of 20 and there were an average of between eight and nine live births per woman living through the childbearing period. There was a steady decline in the average number of live births with advancing age at marriage from age 16 onwards. A significantly high proportion of those dying in the middle of the childbearing period had never married, but the fertility of those marrying at an early age (14, 15 and 16) and dying before reaching the age of 36 was slightly higher than that of those who married at a similar age and survived. Women who survived to the age of 55 were of higher fertility than those who died between the ages of 40 and 55. An analysis of birth intervals revealed significant differences (a) between birth intervals after a stillbirth or after a live birth in which the child died in early infancy, and birth intervals after a live birth in which the offspring survived for longer than 0.4 years, and (b) between the interval from first to second birth and the subsequent birth intervals. There was a difference of almost exactly a year between the average birth interval after a stillbirth or live birth ending in a neo-natal death and the average birth interval after the birth of a child surviving to age 2; there was a similar difference of a year between corresponding median birth intervals.

From 1888 to 1912 infant mortality was well above 300 per thousand. After 1918 infant mortality averaged rather under 100 infant deaths per 1,000 live births. The reduction in infant mortality rates was accompanied by an increase in the mortality of children aged 1 to 4, and the heavy incidence of mortality at these ages after 1918 is the most striking feature of the analysis of mortality by age. Whilst mortality in infancy fell much more heavily on males than on females, early childhood mortality was much higher in Cocos for girls than for boys. The life table computed for the period 1918 to 1947 indicated a life expectancy of about 50 years for males and 47 years for females.     

The influence of nonmarital childbearing on the formation of first marriages

We document a negative association between nonmarital childbearing and the subsequent likelihood of first marriage in the United States, controlling for a variety of potentially confounding influences. Nonmarital childbearing does not appear to be driven by low expectations of future marriage. Rather, it tends to be an unexpected and unwanted event, whose effects on a woman’s subsequent likelihood of first marriage are negative on balance. We find that women who bear a child outside marriage and who receive welfare have a particularly low probability of marrying subsequently, although there is no evidence that AFDC recipients have lower expectations of marriage. In addition, we find no evidence that stigma associated with nonmarital childbearing plays an important role in this process or that the demands of children significantly reduce unmarried mothers’ time for marriage market activities.     

Cohort Trends in Premarital First Births: What Role for the Retreat From Marriage?

We examine cohort trends in premarital first births for U.S. women born between 1920 and 1964. The rise in premarital first births is often argued to be a consequence of the retreat from marriage, with later ages at first marriage resulting in more years of exposure to the risk of a premarital first birth. However, cohort trends in premarital first births may also reflect trends in premarital sexual activity, premarital conceptions, and how premarital conceptions are resolved. We decompose observed cohort trends in premarital first births into components reflecting cohort trends in (1) the age-specific risk of a premarital conception taken to term; (2) the age-specific risk of first marriages not preceded by such a conception, which will influence women’s years of exposure to the risk of a premarital conception; and (3) whether a premarital conception is resolved by entering a first marriage before the resulting first birth (a “shotgun marriage”). For women born between 1920–1924 and 1945–1949, increases in premarital first births were primarily attributable to increases in premarital conceptions. For women born between 1945–1949 and 1960–1964, increases in premarital first births were primarily attributable to declines in responding to premarital conceptions by marrying before the birth. Trends in premarital first births were affected only modestly by the retreat from marriages not preceded by conceptions—a finding that holds for both whites and blacks. These results cast doubt on hypotheses concerning “marriageable” men and instead suggest that increases in premarital first births resulted initially from increases in premarital sex and then later from decreases in responding to a conception by marrying before a first birth.     

Child Marriage in Canada

Child marriage, defined as formal or informal marriage before the age of 18, is a globally recognized indicator of gender inequality. Canada has placed itself at the forefront of global efforts to end child marriage as part of its commitment to the United Nations Sustainable Development Goals. Despite these global aspirations, child marriage remains legal throughout Canada. Data from vital statistics agencies and recent censuses indicate that child marriage, although rare, is practiced across the country. In 2016, nearly 2,300 children between 15 and 17 years of age were in union, a prevalence of 0.2 percent. The vast majority (98 percent) of these were informal, common‐law unions. Demographic patterns of child marriage in Canada are similar to those observed in many low‐ and middle‐income countries. Girls were far more likely to be married as children than boys and typically wed much older spouses. There were marked differences in the prevalence of child marriage across the country, with the highest estimates found in Alberta, Manitoba, Saskatchewan, and the territories. These findings draw attention to the discrepancy between Canada's domestic law and its foreign policy. They also highlight thorny challenges inherent in efforts to eradicate this practice in Canada and elsewhere.     

Age at First Marriage and Age at Death in the Lincolnshire Fenland, 1252–1478

In five Lincolnshire villages between 1252 and 1478 there is evidence that men and women married fairly late before the Black Death, and that by 1348/9 the Western European marriage pattern of late and prudential marriage was well established. Households were usually nucleated; husbands were on average eight years older than their wives before 1348/9, and five years older after 1348/9. Marriages were short: according to the best calculation shorter before 1348/9 than after, most often terminated by the death of the first husband, and were unlikely to produce more than three children. Since there were more males than females amongst children and young adults, many men remained unmarried, but since the death rate of women was very high, men lived longer.     

Proximate determinants of Philippine fertility: 1983 levels and patterns

Data from the 1983 National Demographic Survey are used to analyze the proximate determinants of Philippine fertility in each of the 3 stages of family formation and to identify all of the direct and indirect factors affecting fertility levels and trends. 10,843 ever-married women and 12,771 children were included. The analysis pertains first to the starting patterns of family formation, the age at first birth, and the proximate determinants (age at menarche, age at first marriage/union, conception before first birth, fetal wastage first birth, interval between first marriage and first birth). Further analysis examines birth spacing patterns including the postpartum nonsusceptible period, the exposure interval and stopping patterns. Almost all births occur within marriage, and childbearing begins late at 22.5 years. However, 15.4% of first births are conceived premaritally. The mean age at first birth increases from younger to older cohorts. Urban women were slightly older (23.0 years) at the birth of their first child. Those with education below the 4th grade had first births 3.5 years earlier. Contraceptive use was low at 1.8% before first birth. Younger cohorts were more likely to use birth control and urban wives were more likely to use it than rural wives. 6.4% reported a first pregnancy ending in nonlive births, which were primarily spontaneous abortions (5.2%), stillbirths (1.0%), and induced abortions (.2%). 5.8% report never having been pregnant and 1.1% never having given birth to a live-born child. 20.4% were childless between the ages of 15-24 years, and 4.6% between 25-34 years. Childlessness was slightly higher among urban women (7.1%) than rural women (6.7%). A decreasing age at menarche has appeared; i.e., 13.6 years for the cohort 15-24 years, and 14.0 for the oldest cohort. By age 15, 82.9% had begun menstruating. The mean age at marriage is early at 20.7 years, and older cohorts tended to marry later at 21.4 years. Urban women marry a year later (21.4 years) than rural women. Lower educated women marry 4 years earlier. The mean length between first marriage and first birth was 18.4 months. In the younger cohorts, spacing patterns are shorter. Postpartum susceptibility is short. Return to sexual relations after a birth occurred at 2.8 months. The exposure time required to conceive is fairly long at 16.6 months and is attributed to contraceptive use, since coital frequency is high and temporary separation is infrequent. The average age at last birth is late at 37.6 years.     

Polygyny and the rate of population growth

Summary The roots, motives and feasibility of practising polygyny in societies with a balanced sex structure and the effect of polygyny on the rate of population growth are considered. High demand for labour combined with limited supply over the last several centuries, had been conducive to the evolution of a polygynous nuptiality pattern. The unprecedentedly high rates of population growth during the last several decades combined with progressive economic development have led to a change in the role of the labour factor and consequently diminished its impact upon polygyny. Polygyny is feasible because of a sex-age differential at first marriage, which enables younger cohorts of women to enter the marriage market, and thus results in a very early age at first marriage and universal incidence of marriage among women. A very young pattern of nuptiality inevitably evolves under polygyny, which tends to raise the rate of population growth. No significant variation in fertility between polygynous and monogamous women was found but substantial gaps in standards of living, child mortality, and educational attainment were noted for polygynous households. The findings imply that during the transition from polygyny to monogamy family size will tend to diminish, although initially fertility may not decline concurrently with changing socio-economic status. The most important effects on the rate of population growth thus result from the increase in age at first marriage and declining proportions of ever married women.