Consistent Probabilistic Social Choice

Two fundamental axioms in social choice theory are consistency with respect to a variable electorate and consistency with respect to components of similar alternatives. In the context of traditional non‐probabilistic social choice, these axioms are incompatible with each other. We show that in the context of probabilistic social choice, these axioms uniquely characterize a function proposed by Fishburn (1984). Fishburn's function returns so‐called maximal lotteries, that is, lotteries that correspond to optimal mixed strategies in the symmetric zero‐sum game induced by the pairwise majority margins. Maximal lotteries are guaranteed to exist due to von Neumann's Minimax Theorem, are almost always unique, and can be efficiently computed using linear programming.     

农村养老方式的区域差异与观念嬗变

伴随中国经济社会结构的转型以及人口结构的变化,农村老人的养老观念也在发生变化。通过对东、中、西和东北地区农村老人的问卷调查与深度访谈,初步分析和探讨了农村老人的养老方式及观念变迁问题,并对其进行了区域比较。研究发现,“养儿防老”已变得难以为继,多数老人在可承受范围内进行自我养老,“土地养老”在部分农村地区较为盛行,但却呈现出较为明显的阶段性特征。分地区来看,东部地区较为盛行自我养老,中部地区盛行家庭养老,西部和东北地区则盛行土地养老。究其原因,可从土地条件、经济发展水平和文化传统三个面向对其作出解释。为顺应当前中国农村养老方式和养老观念的发展变化,从可能性、必要性、创新性和实践性四个层面提出了农业养老的构想。     

“全面二孩”后的人口预期与政策展望

“全面二孩”生育政策究竟能对人口发展产生怎样的影响？文章假定今后维持“全面二孩”人口政策不变进行了人口预测。结果可知：城乡全面放开二孩政策并不会带来出生率的猛增和人口数量的剧烈反弹,高峰期最多可以新增出生人口400万;政策调整会提高人口峰值,有利于改善人口结构,延缓劳动力供给的衰减速度,但作用微乎其微。从其他国家的人口发展经验看,生育率的下降趋势似乎不可避免。因此,“全面二孩”并不是生育政策调整的终点,应继续监测生育水平,进一步调整生育政策;建立和完善“家庭友好”政策体系;从社会体制和经济体制应对负面影响。     

Nonparametric Estimation of the Number of Drug Users in Hong Kong Using Repeated Multiple Lists

We update a previous approach to the estimation of the size of an open population when there are multiple lists at each time point. Our motivation is 35 years of longitudinal data on the detection of drug users by the Central Registry of Drug Abuse in Hong Kong. We develop a two‐stage smoothing spline approach. This gives a flexible and easily implemented alternative to the previous method which was based on kernel smoothing. The new method retains the property of reducing the variability of the individual estimates at each time point. We evaluate the new method by means of a simulation study that includes an examination of the effects of variable selection. The new method is then applied to data collected by the Central Registry of Drug Abuse. The parameter estimates obtained are compared with the well known Jolly–Seber estimates based on single capture methods.     

老龄化背景下社会养老服务体系需求研究 ——以滁州市为例

已有的以“居家为基础、社区为依托、机构为支撑”的社会养老服务体系实际运行中未达到预期效果,存在目标人群模糊, 核心功能不清等问题。通过滁州市居民养老服务需求的调查,构建需求=意愿×能力的模式,研究老人养老服务意愿,支付养 老服务的能力,提出以照护为核心,在居家养老基础上对空巢、独居老人加强社区综合平台的作用,突出高龄、失能、半失能老 人机构养老的支撑作用,引进社会力量,以满足老年人群多样化多层次需求     

Choosing summary statistics by least angle regression for approximate Bayesian computation

Bayesian statistical inference relies on the posterior distribution. Depending on the model, the posterior can be more or less difficult to derive. In recent years, there has been a lot of interest in complex settings where the likelihood is analytically intractable. In such situations, approximate Bayesian computation (ABC) provides an attractive way of carrying out Bayesian inference. For obtaining reliable posterior estimates however, it is important to keep the approximation errors small in ABC. The choice of an appropriate set of summary statistics plays a crucial role in this effort. Here, we report the development of a new algorithm that is based on least angle regression for choosing summary statistics. In two population genetic examples, the performance of the new algorithm is better than a previously proposed approach that uses partial least squares.     

不同城市的房价是否具有相同的人口集聚效应——基于35个大中城市PVAR模型的实证分析

人口集聚会引起房价上涨,但不同类型的城市由于集聚人口的教育程度不同,房价上涨也具有不同的效应。首先建立人口流动理论模型分析人口集聚对房价上涨的影响,然后通过建立房价、人口集聚、房地产投资和人均可支配收入的PVAR模型进行实证分析。结论表明,一类城市人口集聚对房价上涨具有正效应,二类城市为平效应,三类城市为负效应;三类城市的房价上涨主要是房地产投资和人均收入提高所推动的。     

福建省“十一五”期间人口变化与人力资源供给分析

人口预测和人力资源供给分析是为了适应社会经济发展的客观需要而提出的,它们未来的发展状况,对于一个地区的社会经济的发展影响深远。在对福建省"十五"期间人口与人力资源状况分析的基础上,对福建省"十一五"期间人口与人力资源状况进行初步预测,旨在为福建省制定未来的社会经济发展战略提供人口统计上的数据依据。     

Reconstruction of populations by stochastic optimization: Sensitivity analysis

The reconstruction of populations by stochastic optimization solves the nontrivial problem of finding demographic flows from population registers or vital statistics and censuses, if available. These flows allow the reconstruction of stocks (age pyramids and vital statistics). After a review of reconstruction methods, the sensitivity analysis shows the robustness of the method by stochastic optimization to flawed or missing values, to the length of the reconstruction period, and to variations in the actual demographic flows.     

计划生育工作新机制与人口管理科学的发展

计划生育工作新机制反映了人口管理科学的发展。回顾人口管理学的发展历史,研究我国计划生育工作从旧机制转向新机制,与人口管理科学从传统走向现代的密切联系,积极推动人口管理科学的进一步发展。