BACKGROUND: The long-term decline in cohort fertility in highly developed countries has been widely documented. However, no systematic analysis has investigated which parity contributed most to the fertility decline to low and very low levels. Objective: We examine how the contribution of changing parity progression ratios varied across cohorts, countries, and broader regions in Europe, North America, Australia, and East Asia. We pay special attention to countries that reached very low completed cohort fertility, below 1.75 children per woman. Methods: Using population censuses and large-scale surveys for 32 low fertility countries, we decompose the change in completed cohort fertility among women born between 1940 and 1970. The decomposition method takes into account the sequential nature of childbearing as a chain of transitions from lower to higher parities. Results: Among women born between 1940 and 1955, the fertility decline was mostly driven by reductions in the progression ratios to third and higher-order births. By contrast, among women born between 1955 and 1970, changes in fertility showed distinct regional patterns: In Central and Eastern Europe they were fuelled by falling second-birth rates, whereas in the German-speaking countries, Southern Europe, and East Asia decreases in first-birth rates played the major role. Conclusions: Pathways to low and very low fertility show distinct geographical patterns, which reflect the diversity of the cultural, socioeconomic, and institutional settings of low fertility countries. Contribution: Our study highlights the importance of analysing parity-specific components of fertility in order to understand fertility change and variation. We demonstrate that similar low levels of completed cohort fertility can result from different combinations of parity-specific fertility rates.

Ce mémoire regroupe différentes études sur la préférence pour les garçons au Pakistan. Celles-ci analysent la fréquence et l'étendue de la préférence pour les garçons et son effet sur la grossesse des femmes. Le rôle que la préférence pour les garçons joue sur la participation des femmes au niveau des décisions au sein du ménage est examiné, tout comme son effet sur l'espacement des naissances, la probabilité d'une naissance à risque, ou l'impact de l'âge auquel une femme se marie sur l'équilibre entre les sexes et le développement de l'enfant né. Nous trouvons qu'il existe une préférence réelle et déclarée pour la progéniture masculine au Pakistan. La probabilité de poursuivre les grossesses diminue avec le nombre de garçons nés. De plus, les femmes qui ont au moins un garcon ont plus d'influence sur les décisions quotidiennes du ménage mais pas sur les décisions financières. La participation des femmes sur les décisions à prendre au sein du ménage augmente avec le nombre de garçons mais seulement jusqu'à la troisième naissance. D'ailleurs, les femmes ayant au moins un garçon attendent plus longtemps avant d'avoir d'autres enfants. Ce constat est plus particulièrement vrai dans le cadre d'une première naissance et il est moins présent à partir de la deuxième naissance. En outre, le fait de se marier à 18 ans ou plus tard influence de façon positive la préférence des femmes sur la composition de sa famille. Pourtant, peu importe qu’une femme se marie avant ou après 18 ans, cela ne modifie pas le biais en faveur des garçons dans leur investissement parental. A partir de ces résultats, nous proposons des préconisations politiques afin de lutter contre les inégalités entre les sexes au Pakistan. / This thesis is a collection of studies on son preference in Pakistan. The studies analyze the prevalence and strength of son preference and its effects on women’s childbearing. The role son preference plays in determining women's participation in intra-household decisionmaking is examined as are its effect on birth spacing, probability of risky births and role of maternal age at marriage in modifying gender-specific reproduction and development outcomes. We find strong evidence for both the revealed and stated preference for male offspring. The probability of continuing childbearing also decreases with the number of sons born. Furthermore, we find that women with at least one son have more say in ‘routine’ household decisions but not in financial decisions. Female participation in decision-making grows significantly with the number of sons but only up to the third parity. We find that women with at least one son are more likely to delay succeeding births. We obtain strong evidence at parity 1. The impact seems to dissipate beyond the second parity. Moreover, we find that marriage at 18 or later positively influence women’s preference for family’s sex composition. However, whether or not a woman married early or late does little to modify the male gender bias prevalent in parental investment. In light of these findings, we suggest policy measures that could help improve gender equity in the country.

台灣地區生育率逐年下降，從1985年起總生育率即低於替代水準2.1；近幾年更快速下降，2005年降至空前的1.12，僅有1960年的1/6。為瞭解台灣地區生育率的未來趨勢，本文研究婦女生育年齡、勞動參與率、教育程度及胎次生育率，與世界各國比較，以分析生育率的變化。我們發現近年台灣、日本及法國各年齡組對生育率的貢獻幾乎相同，但法國的總生育率卻有2的水準。比較台灣地區大專以上及高中以下教育程度的婦女，兩者的生育情況在早期是有所差別的，但近年兩者的生育行為非常接近；大學以上及高中以下的婦女生育率均同時降低，生育率的下降似乎和婦女教育程度關係不大。除了以年齡別的角度進行分析，本文也在胎次別生育率的研究上探討及驗證過去的模型與理論，提出模型以修正Feeney的胎次進級模型，從台灣地區資料的計算結果來比較，兩者相差不大，建議在資料允許的情況下可以使用我們提出的計算方法。 / The fertility rates in Taiwan decline rapidly. The total fertility rate has been lower than the replacement level 2.1 since 1985 and it reached to 1.12, the historical low in 2005, only 1/6 of which in 1960. In order to explore the fertility trend in Taiwan, several variables were used to compare with countries in the world, including women fertility rate by age groups, female labor force participation rate, fertility of women with different educational attainments and fertility rate by birth order. We found that Taiwan, Japan and France share a similar fertility pattern, unlike in the U.S., while the young female groups still have significant contribution on fertility. For the variable of highest education attained, the group of senior high school and below have higher fertility before 1970’s comparing to that of education with college and higher. However, the gap narrowed down in recent years. Also, for the fertility rates by birth order, we proposed a new model estimation for the parity progression model. We found that the results of proposed method are almost identical to those of the original method, but the computation is much easier.

The objective behind this study was to mathematically analyse, model and forecast the vital rates (mortality and fertility) of Nepal. In order to attain this goal, the data have been converted into tables and analysed intensively using several softwares such as Mocrosoft Excel, SPSS, Mathematica. The margin of error of data has been analysed. In Chapter 4, the error and uncertainity in the data have been analysed using Bayesian analysis. The reliability of the data of Nepal has been compared with the reliability of the data of Germany. The mortality and fertility conditions of Nepal have been compared from two angles. Data on India (particularly north India) have provided comparison on the socio-economic grounds whereas data on Germany(with accurate and abundant data) have provided comparison on the ground of data availability and accuracy. Thus in addition to analysing and modeling the data, the regional behaviour has been studied. The limited and defective data of Nepal have posed a challange at every stage and phase. Because of this very long term forecasting of mortality could not be made. But the model has provided a lot of information on the mortality for the years for which the data were lacking. But in the comming future, with new data at hand and with the new models developed here, it could be possible to do long term projections. In the less developed world, rural and urban areas have a big impact on the mortality and fertility of a country. The rural and urban effects on mortality and fertility have been studied individually. While analyzing the mortality scene of Nepal, it has been observed that the mortality is decreasing. The decrease is slow, but it reflects the advancement in medical facilities and health awareness. The fertility is also decreasing. There is a decrease in the number of children per woman and per family. This decrease is more pronounced in the urban areas as compared to the rural areas. This also reflects that the family planning programmes launched are showing results, particularly in urban areas.