子女数量对家庭收入的影响

基于2005年全国1%人口抽样调查数据,利用生育偏好和生育政策的城乡差异构造工具变量,实证分析子女数量对家庭收入的影响。结果显示,子女数量的增加显著抑制家庭收入的提升,生育二胎导致家庭收入平均下降20.8%。此外,这种负向影响还表现出显著的城乡差异,农村家庭生育二胎使得家庭收入显著下降8.8%,而城镇家庭收入则下降21.2%。进一步地,区分是否三代同住以及母亲职业类型家庭的异质性分析结果显示,在非三代同住家庭、母亲在机关企事业单位任领导职务或从事专业技术类职业的家庭中,子女数量对家庭收入均具有显著的负向影响。分析结论凸显了宏观层面人口结构调整和居民收入提升以及微观层面生育决策与家庭收入之间的双重权衡。     

Analysis of the human sex ratio by using overdispersion models

For study of the human sex ratio, one of the most important data sets was collected in Saxony in the 19th century by Geissler. The data contain the sizes of families, with the sex of all children, at the time of registration of the birth of a child. These data are reanalysed to determine how the probability for each sex changes with family size. Three models for overdispersion are fitted: the beta–binomial model of Skellam, the 'multiplicative' binomial model of Altham and the double-binomial model of Efron. For each distribution, both the probability and the dispersion parameters are allowed to vary simultaneously with family size according to two separate regression equations. A finite mixture model is also fitted. The models are fitted using non-linear Poisson regression. They are compared using direct likelihood methods based on the Akaike information criterion. The multiplicative and beta–binomial models provide similar fits, substantially better than that of the double-binomial model. All models show that both the probability that the child is a boy and the dispersion are greater in larger families. There is also some indication that a point probability mass is needed for families containing children uniquely of one sex.     

Two decades of family change: secondary analysis of continuous government surveys

"Secondary analysis of General Household Survey and Labour Force Survey data shows how the structure of families in Great Britain has changed over the last 20 years. Dependent children are now less likely to be living in a couple family and more likely to be living with a lone mother who is either single or divorced. Families in simple households with just two generations have become more common over time. Lone mothers are now more likely to be living in simple households. The paper also considers how the number and ages of dependent children are associated with family and household type. Log-linear models are used both to smooth the data and to predict family structure in the year 2000. Gaps in our knowledge about current family structures are discussed together with implications of the findings for social policy."     

Sibling death clustering in India: state dependence versus unobserved heterogeneity

Summary.  Data from a range of environments indicate that the incidence of death is not randomly distributed across families but, rather, that there is a clustering of death among siblings. A natural explanation of this would be that there are (observed or unobserved) differences across families, e.g. in genetic frailty, education or living standards. Another hypothesis that is of considerable interest for both theory and policy is that there is a causal process whereby the death of a child influences the risk of death of the succeeding child in the family. Drawing language from the literature on the economics of unemployment, the causal effect is referred to here as state dependence (or scarring). The paper investigates the extent of state dependence in India, distinguishing this from family level risk factors that are common to siblings. It offers some methodological innovations on previous research. Estimates are obtained for each of three Indian states, which exhibit dramatic differences in socio-economic and demographic variables. The results suggest a significant degree of state dependence in each of the three regions. Eliminating scarring, it is estimated, would reduce the incidence of infant mortality (among children who are born after the first child) by 9.8% in the state of Uttar Pradesh, 6.0% in West Bengal and 5.9% in Kerala.     

On Comparison of Stopping Times in Sequential Procedures for Exponential Families of Stochastic Processes

For curved ( k + 1), k -exponential families of stochastic processes a natural and often studied sequential procedure is to stop observation when a linear combination of the coordinates of the canonical process crosses a prescribed level. For such procedures the model is, approximately or exactly, a non-curved exponential family. Subfamilies of these stopping rules defined by having the same Fisher (expected) information are considered. Within a subfamily the Bartlett correction for a point hypothesis is also constant. Methods for comparing the durations of the sampling periods for the stopping rules in such a subfamily are discussed. It turns out that some stopping times tend to be smaller than others. For exponential families of diffusions and of counting processes the probability that one such stopping time is smaller than another can be given explicity. More generally, an Edgeworth expansion of this probability is given     

Approximating the distribution of a renewal process using generalized poisson distributions

The exact distribution of a renewal counting process is not easy to compute and is rarely of closed form. In this article, we approximate the distribution of a renewal process using families of generalized Poisson distributions. We first compute approximations to the first several moments of the renewal process. In some cases, a closed form approximation is obtained. It is found that each family considered has its own strengths and weaknesses. Some new families of generalized Poisson distributions are recommended. Theorems are obtained determining when these variance to mean ratios are less than (or exceed) one without having to find the mean and variance. Some numerical comparisons are also made.     

Conditionally Reducible Natural Exponential Families and Enriched Conjugate Priors

Consider a standard conjugate family of prior distributions for a vector-parameter indexing an exponential family. Two distinct model parameterizations may well lead to standard conjugate families which are not consistent, i.e. one family cannot be derived from the other by the usual change-of-variable technique. This raises the problem of finding suitable parameterizations that may lead to enriched conjugate families which are more flexible than the traditional ones. The previous remark motivates the definition of a new property for an exponential family, named conditional reducibility. Features of conditionally-reducible natural exponential families are investigated thoroughly. In particular, we relate this new property to the notion of cut, and show that conditionally-reducible families admit a reparameterization in terms of a vector having likelihood-independent components. A general methodology to obtain enriched conjugate distributions for conditionally-reducible families is described in detail, generalizing previous works and more recent contributions in the area. The theory is illustrated with reference to natural exponential families having simple quadratic variance function.     

Demographic policy in the light of the resolutions of the Twenty-sixth Congress of the Communist Party

The USSR is moving from extensive to intensive type of population reproduction, not because of any governmental measures but as a reaction to objective circumstances. At present there is a reduction in the population cohort of working age. This has an adverse effect on production. And the number of the elderly is increasing; we must involve them more in the production process, in monitoring the service sphere, for instance. The infant mortality rate has declined sharply in the USSR, especially since World War II. The birthrate has also dropped, but it is still higher than in the US, France, or West Germany. Some authorities think that this (the ZPG) is a good idea, but this author thinks it is a bad idea, meaning a drop in society's productive forces. We need an active demographic policy, meaning one which ensures optimal reproduction of the population with an improvement in its health, culture, and living standard. The policy must be differentiated, as conditions vary from one part of the country to another. An example is the 1981 decree on assistance to families with children which provides for payments of 35-50 rubles/month to mothers who must stay home to look after children. The number of children per family to ensure reproduction must be 2.6 on the average. In the Central Asian republics family sizes of 4-5 children are anticipated, but in the RSFSR, Ukraine, Belorussia, and the Baltic republics the anticipated size of families is rather low. Measures must be taken to alter this by providing assistance to families with children.     

Model-based clustering, classification, and discriminant analysis via mixtures of multivariate t-distributions

The last decade has seen an explosion of work on the use of mixture models for clustering. The use of the Gaussian mixture model has been common practice, with constraints sometimes imposed upon the component covariance matrices to give families of mixture models. Similar approaches have also been applied, albeit with less fecundity, to classification and discriminant analysis. In this paper, we begin with an introduction to model-based clustering and a succinct account of the state-of-the-art. We then put forth a novel family of mixture models wherein each component is modeled using a multivariate t-distribution with an eigen-decomposed covariance structure. This family, which is largely a t-analogue of the well-known MCLUST family, is known as the tEIGEN family. The efficacy of this family for clustering, classification, and discriminant analysis is illustrated with both real and simulated data. The performance of this family is compared to its Gaussian counterpart on three real data sets.     

Statistical materials. Results of the 1985 socio-demographic sample survey of the population

Results from the five percent socio-demographic sample survey of the USSR conducted in 1985 are presented. Data are provided on the educational status of the population and the labor force by nationality, republic, sex, and rural or urban area; income; marital status; marriage duration; divorce and separation; intervals between marriages; family size; family characteristics; families with children under 18; internal migration; and distribution of women by number of children ever born, republic, nationality, educational status, and expected family size     

Parental partnership and joblessness in childhood and their influence on young people's outcomes

Summary.  The paper estimates the relationship between several outcomes in early adulthood (education, inactivity, early birth, distress and smoking) and experiences of life in a single-parent family and with jobless parent(s) during childhood. The analysis is performed using a sample of young adults, who are selected from the first nine waves of the British Household Panel Survey (1991–1999) and can be matched with at least one parent and one sibling over the same period. This sample allows us to estimate the relationship of interest by using sibling differences. We also use another sample of young adults from the British Household Panel Survey, matched to at least one parent, to estimate more conventional level models and to compute nonparametric bounds and point estimates. The estimates based on sibling differences require weaker assumptions (compared with the assumptions that are imposed by nonparametric estimators under conditional independence and level estimators) for the identification of the effects of family structure and parental joblessness on the outcomes under analysis. We find that experiences of life in a single-parent family and with jobless parents during childhood are usually associated with disadvantageous outcomes for young adults, the effect of family structure is in general significantly greater (in absolute value) than the effect of parental worklessness and most of the unfavourable outcomes are linked to an early family disruption, when the child was aged 0–5 years, whereas the timing of parental joblessness during childhood has more complex effects, with different outcomes being more strongly influenced by parental worklessness at different ages of the child.     

家庭式迁移女性农民工劳动供给行为研究

随着城市化的不断推进,家庭式迁移已经成为农民工流动的重要模式。家庭式迁移的女性农民工需要同时扮演雇佣劳动者和家务主要承担者的双重角色,这种迁移模式对女性的劳动供给行为会造成重大的影响。利用浙江省农民工的调查数据,试图考察家庭式迁移女性农民工劳动供给的影响因素。分析结果表明:工作经验、培训经历、本地生活时间、工资对女性农民工的劳动供给具有显著影响;家庭结构的影响不显著,但子女或老人随迁会显著降低女性的劳动参与率和工作时间;分位数回归结果表明,各因素对女性工作时间不同分位数上的影响具有明显变化。     

Multivariate Positive Dependence on the Simplex

The Liouville and Generalized Liouville families have been proposed as parametric models for data constrained to the simplex. These families have generated practical interest owing primarily to inadequacies, such as a completely negative covariance structure, that are inherent in the better-known Dirichlet class. Although there is some numerical evidence suggesting that the Liouville and Generalized Liouville families can produce completely positive and mixed covariance structures, no general paradigms have been developed. Research toward this end might naturally be focused on the many classical "positive dependence" concepts available in the literature, all of which imply a nonnegative covariance structure. However, in this article it is shown that no strictly positive distribution on the simplex can possess any of these classical dependence properties. The same result holds for Liouville and generalized Liouville distributions even if the condition of strict positivity is relaxed.     

A PROBLEM IN ASCERTAINMENT

In studies of disease inheritance, it is more convenient to collect family data by first locating an affected individual and then enquiring about the status of his or her relatives. Although the different categories of children classified by disease, sex, and other covariates may have a particular multinomial distribution among families of a given size, the numbers as ascertained do not have the same distribution because of unequal probabilities of selection of families. The introduction of weighted distributions to correct for ascertainment bias in the estimation of parameters in the classical segregation model can be traced to Fisher in 1934. This theory was presented in a general formulation by C. R. Rao at the First International Symposium on Classical and Contagious Distributions in 1963. Further expansion on the topic was given by C. R. Rao in the ISI Centenary Volume published in 1985. The effects of different two-phase sampling designs on the estimation of parameters in the classical segregation model are examined. An approximation to the classical segregation likelihood model is found to produce results close to those of the exact likelihood function in Monte Carlo simulations for a balanced two-phase design. This has implications for more complex models in which the computation of the exact likelihood is prohibitive, such as for the enhancement of a typical survey sampling plan designed initially for linkage analysis but then used retroactively for a combined segregation and linkage analysis.     

Two classes of divergence statistics for testing uniform association

The problem of testing uniform association in cross-classifications having ordered categories is considered. Two families of test statistics, both based on divergences between certain functions of the observed data, are studied and compared. Our theoretical study is based on asymptotic properties. For each family, two consistent approximations to the null distribution of the test statistic are studied: the asymptotic null distribution and a bootstrap estimator; all the tests considered are consistent against fixed alternatives; finally, we do a local power study. Surprisingly, both families detect the same local alternatives. The finite sample performance of the tests in these two classes is numerically investigated through some simulation experiments. In the light of the obtained results, some practical recommendations are given.     

Childhood mortality spatial distribution in Ethiopia

The risk of a child dying before completing five years of age is highest in Sub-Saharan African countries. But Child mortality rates have shown substantial decline in Ethiopia. For this study, the 2000, 2005 and 2011 Ethiopian Demographic Survey (EDHS) was used. Generalized linear mixed model with spatial covariance structure was adapted. The model allowed for spatial correlation, and leads to the more realistic estimate for under-five mortality risk factors. The analysis showed that the risk of under-five mortality shows decline in years. But, some regions showed increase in years. The study highlights the need to implement better education for family planning and child care to improve the under-five mortality situation in some administrative areas.     

A Comparison of Methods for Analysing a Nested Frailty Model to Child Survival in Malawi

Demographic and Health Surveys collect child survival times that are clustered at the family and community levels. It is assumed that each cluster has a specific, unobservable, random frailty that induces an association in the survival times within the cluster. The Cox proportional hazards model, with family and community random frailties acting multiplicatively on the hazard rate, is presented. The estimation of the fixed effect and the association parameters of the modified model is then examined using the Gibbs sampler and the expectation–maximization (EM) algorithm. The methods are compared using child survival data collected in the 1992 Demographic and Health Survey of Malawi. The two methods lead to very similar estimates of fixed effect parameters. However, the estimates of random effect variances from the EM algorithm are smaller than those of the Gibbs sampler. Both estimation methods reveal considerable family variation in the survival of children, and very little variability over the communities.     

论孩子的教育费用及其决定因素

口再生产的质量很大程度上决定于教育资源的投入,是理论界早已形成的共识。最早运用经济学的理论和方法研究生养孩子的成本和效用的西方学者莱宾斯坦把孩子接受教育的费用作为一个重要的构成计入抚养孩子的直接成本。诺贝尔经济学奖获得者美国著名经济学家贝克尔则把孩子...     

中等收入群体的持续期与退出风险估计———基于EM算法的收入群体划分

本文在利用EM算法求解有限混合分布模型以识别CFPS数据库中各年度中等收入群体的基础上,使用生存分析方法估计了中等收入群体的持续期与退出风险。两种情境下的估计结果显示,20%以上的中等收入家庭在样本期内表现出了脆弱性,这意味着传统的仅考虑一期家庭收入状态的中等收入群体比例测算可能高估了真实的中等收入群体比例。此外,家庭面临倒U型退出风险,持续期与退出风险存在显著的区域与城乡间差异:东部地区与城市地区的中等收入家庭表现出更强的收入稳固性。本文还进一步分析了家庭退出中等收入群体的决定因素,估计结果表明,家庭收入结构、家庭人口特征、家庭职业特征等因素对家庭退出风险影响显著。     

On the eve of birth control. II

The results of a 1981 sample survey on family planning in Poland show that the average birth ratio for couples married in 1975 is 2.1 (2.0 in the cities and 2.5 in rural areas). With a much lower mortality rate, this minimal reproduction ratio still provides the fairly high natural population growth which is characteristic of all industrialized nations. This birth ratio is maintained by almost universal use of various birth control methods after 6-7 years of marriage, i.e., an average family with 2 children is planned and created by means of contraceptives and abortions. The family planning situation in Poland is discussed for women who: 1) plan to have more children, 2) might change their decision not to have more children, and 3) made a final decision not to have more children. The reasons for these decisions are thoroughly analyzed. Particular attention is paid to the extent to which couples are able to reach their reproductive objectives. The analysis indicates that many couples would have had more children if the husband received a higher salary, housing conditions were better, and the mother could quit her job for at least some period of time. Birth control is used because most couples are satisfied with having 2 children and consider their reproductive objectives fulfilled.