Son preference in Bangladesh: an emerging barrier to fertility regulation

This study investigates the effect of son preference on contraceptive use and desire for additional children using national level survey data from Bangladesh for the years 1969 and 1979. National probability samples of ever married women between the ages of 10 and 50 were selected and stratified by urban-rural residence. Specifically, the study focuses on contraceptive use and desire for additional children and separates the effect of sex preference from that of high parity on fertility control. Son preference has a negative effect on contraceptive use and a positive effect on the desire for additional children regardless of socioeconomic and demographic characteristics. This advese effect of son preference on fertility regulation seemed to have persisted over the years. Relevent socioeconomic conditions in Bangladesh are described. In 1979, the effect of sex composition on contraceptive use or desire for additional children varied by parity. The negative effect of fewer living sons on contraceptive use and its positive effect on desire for additional children was higher in parities between 2 and 4 than in other parities. The effect of sex composition was stronger on desire for additional children than on contraceptive usage. In 1969, however, there was no consistent positive relationship between sex composition and contraceptive use. The relationship between sex composition and desire for more children was positive. Among women of parities 2 to 4, an excess of daughters continued to have a major positive effect on desire for additional children, and a negative effect on contraceptive use, after controlling for other sociodemographic variables. For parities 1 and 5 or above, the effect was either weak or inconsistent.     

Son preference and the sex ratio at birth in China: A provincial level analysis

Abstract

Data from a Samoan menstruation study suggest that lactation, even intensive on‐demand lactation, does not inhibit menstruation or conception. This paper explores the applied and theoretical implications of continuing to accept lactation as a universally effective fertility control mechanism. Such thinking can have disastrous implications for family planning programs, and it keeps us from challenging long‐held assumptions about lactation's role in population growth in early populations.     

Son preference among Filipino Muslims: A causal analysis

Abstract

A social selection model for deleterious genes has been studied by considering two alleles at one locus. The model allows for the fitness of an individual to be determined by parental phenotypes as well as by his/her own phenotype. We show that the equilibrium gene frequency depends on the loss of fitness of an individual due to the trait (γ) and due to affected parents (P), and the probability that the heterozygote develops the trait (h). We show that whenever an interior equilibrium point exists for given values of γ and β, it is unique and that the sufficient condition for the existence of the equilibrium point is given by     

Son preference and child replacement in Bangladesh: a new look at the child survival hypothesis

Birth history data from women in the 1975-76 Bangladesh Fertility Survey were used to search for intentions to replace dead children. The median intervals between successive births of orders (i) and (i + 1) were not shorter when some siblings of orders below (i) had died. Nor was the median duration between the death of a child and the first posthumous birth shorter when the dead child was a boy or when it was survived by fewer than two brothers. The median intervals were generally shorter when the mother lived in an urban rather than a rural area but this difference was attributable only to the shorter duration of breast-feeding by urban women. These results disputed the notions that the timing of births was deliberately quicker to replace a dead child, that attempts at replacement were sex-selective, or that child replacement intentions were stronger in urban than in rural populations.     

Son preference and intimate partner violence victimization in India: examining the role of actual and desired family composition

Son preference has been considered as a determinant of women's risk of intimate partner violence (IPV) experience in India, although quantitative evidence from large nationally representative studies testing this relationship is limited. This study examines the association between husband's son preference, sex composition of children and risk of physical and sexual IPV victimization among wives. Information was collected for 26,284 couples in the nationally representative 2005-2006 National Family Health Survey of India. The exposures were husband's son preference measured as husband's desire for one or more sons greater than the number of daughters and sex composition of the household: only sons, only daughters and mixed. Outcome included past year physical and/or sexual IPV. The results showed that husband's reported son preference (RR: 1.05; 95% CI: 0.98-1.13) and sex composition of children were not associated with risk for IPV victimization in the models adjusted for socio-demographic factors. The findings from this first population-based study of socio-cultural norms around son preference and married Indian women's risk for IPV victimization indicate that cultural preference for sons does not influence women's risk for IPV victimization.     

Socioeconomic structure and fertility in China: a county level investigation

Analysis of the general fertility rate in the counties of China shows significant associations with infant mortality, illiteracy, and the percentage of the population employed in industry, but not with industrial or agricultural output. Urban counties differ from rural in the importance of the illiteracy rate. The associations in the rural counties vary according to the region of China in which they are located.     

Matriarchy, polyandry, and fertility amongst the Mosuos in China

A survey of 232 households of the Mosuo minority group in Yunnan Province, People's Republic of China, suggested that polyandrous matriarchy did not raise the birth rate per household, but lowered the community birth rate by restricting many women's chances of marrying. The results imply that tolerance by the national government of polyandry within certain minority groups (e.g. Mosuos and Tibetans) will not prevent but may aid the attainment of zero population growth by China in the twenty-first century.     

Age at first marriage and fertility in rural Anhui, China

This paper examines the changing nuptiality pattern of rural China, particularly rural Anhui in relation to the planned social changes since 1949 and their effect on fertility. The data are from the 1/1000 Fertility Survey of China, conducted by the Family Planning Commission in 1982. Before the family planning programme was introduced to rural Anhui (1972), the changing nuptiality pattern was indirectly affected by the planned social changes; after 1972, the substantial increase in age at first marriage was mainly due to the family planning programme. More recently, the centrally controlled social structure is loosening, due to the economic reform and the nuptiality pattern seems to join the 1972 trend, suggesting that the dramatic change of nuptiality pattern during the early 1970s to early 1980s was a temporary one. But its effect on fertility is clear, and the shortening interval between marriage and first birth may bring difficulties for future population control in rural China.     

Soil organic carbon budget and fertility variation of black soils in Northeast China

Black soils in Northeast China are characteristic of high soil organic carbon (SOC) density and were strongly influenced by human activities. Therefore, any change in SOC pool of these soils would not only impact the regional and global carbon cycle, but also affect the release and immobilization of nutrients. In this study, we reviewed the research progress on SOC storage, budget, variation, and fertility under different scenarios. The results showed that the organic carbon storage of black soils was 646.2 TgC and the most potential sequestration was 2887.8 g m⁻². According to the SOC budget, the net carbon emission of black soils was 1.3 TgC year⁻¹ under present soil management system. The simulation of CENTURY model showed that future climate change and elevated CO₂ concentration, especially the increase of precipitation, would increase SOC content. Furthermore, fertilization and cropping sequence obviously influenced SOC content, composition, and allocation among different soil particles. Long-term input of organic materials such as manure and straw renewed original SOC, improved soil structure and increased SOC accumulation. Besides, soil erosion preferred to transport soil particles with low density and fine size, decreased recalcitrant SOC fractions at erosion sites and increased activities of soil microorganism at deposition sites. After natural grasslands were converted into croplands, obvious variation of soil chemical nutrients, physical structure, and microbial activities had taken place in surface and subsurface soils, and represented a degrading trend to a certain degree. Our studies suggested that adopting optimal management such as conservation tillage in black soil region is an important approach to sequester atmospheric CO₂ and to slow greenhouse effects.     

Polygamy and fertility in Somalia

The 1983 Somali Family Health Survey showed that polygamy and monogamy selected women with different social characteristics. Wives in polygamous unions were prone to be younger at first martial cohabitation and to have previous marital disruptions. Since a young age at first cohabitation and number of previous marriages have opposite effects on the cumulative fertility rate of women, the difference in this rate between wives in polygamous and monogamous unions vanished when both factors were controlled in a multivariate analysis.     

Ethnicity and fertility in Nigeria

Using a sample of Hausa-Fulani, Yoruba, Ibo, and all other women from the 1990 Nigerian Demographic and Health Survey, this study examines ethnic fertility differentials in Nigeria within the context of the social characteristics and cultural hypotheses. Among all women, we find the net fertility of Hausa-Fulani women to be lower than that of Other women; with no statistically significant difference in the net fertility of Ibo, Yourba, and Other women. But, among currently married women, we find the net fertility of Hausa-Fulani and Yoruba women to be lower than that of Other women, while the net fertility of Ibo women is higher than that of Other women. Overall, the findings of this study are more consistent with the cultural hypothesis, because statistically significant fertility differentials by ethnicity remain, even after controlling for selected socioeconomic and demographic variables.     

Variations in historical natural fertility patterns and the measurement of fertility control

This paper looks at 2 main issues: 1) Henry's definition of natural fertility--that which is not controlled within marriage in a parity-specific way; and 2) the use of standard age-specific marital fertility schedules to measure the extent of fertility control. The authors note a number of conceptual difficulties inherent in Henry's definition and which detract from its usefulness. In particular, prolonged lactation and taboos against sexual intercourse are capable of depressing fertility within marriage, while still allowing it to be described as natural. This paper explores some of the consequences of the identified difficulties for the measurement of fertility control within marriage. Regional as well as temporal variations are to be expected in the pattern of marital fertility. The factors affecting natural fertility may be broadly divided into the physical and the psychological. Needed are a variety of standard marital fertility schedules specific to the underlying fertility conditions of the particular population under investigation. The universal applicability of a single standard is placed in doubt. The greatest problem, however, with the application of the idea of natural fertility to historical populations is that its definition rests upon a number of behavioral characteristics amongst a population, whereas its identification must normally proceed in reverse, arguing backwards from the pattern observed to the behavioral processes and conditions which might have produced that pattern. The arguments presented are illustrated by a detailed example drawn from the fertility patterns of Britain, Denmark and Sweden.     

南方地区秸秆还田对土壤综合肥力和作物产量的影响

以安徽、江西、湖南、湖北、四川、重庆、广西等省94个秸秆还田定位试验为基础,运用数值化理论综合评价我国南方地区秸秆还田的土壤肥力变化和培肥增产效应.结果表明:研究区土壤肥力综合指数(SFI)和作物产量具有明显的区域差异,但SFI整体以中等水平的三等地(该等级土地面积占研究区土地面积的69.1％)和较低水平的四等地(占21.3％)为主;秸秆还田后,SFI和产量较秸秆不还田平均提高了6.8％和4.4％;水稻产量与SFI之间呈极显著正相关.SFI可真实反映研究区土壤肥力综合水平.在当前农艺水平下,秸秆还田是有效提高我国南方地区土壤综合肥力的重要举措,应大面积推广秸秆还田腐熟.     

Thyroid and fertility

The aim of this work is to specify the relationship between the thyroid function and the hypothalamo-hypophyso-gonadal axis. Qualitative and quantitative repercussions of a thyroid pathology on human or animal fertility, male or female are very variable. A review of mechanisms of action is presented, illustrating: the complexity of the phenomena in cause; the necessity not to dissociate thyroid and reproductive function either clinically or biologically; the serious consequences of either undetected or untreated neo-natal thyroid pathology.