Parametrizing the Kepler exoplanet period-radius distribution with the bivariate normal inverse Gaussian distribution

This paper presents a simple and robust method for obtaining a comprehensive understanding of the joint period and radius distribution in Kepler exoplanets. The proposed method is based on particle swarm optimization and bivariate Normal Inverse Gaussian distribution. Furthermore, in the construction of the probability density function, this study selects planet-host stars with the GK-type. The injecting approach is also employed to solve the survey completeness of sample. The resulting occurrence rate of Earth analogs is 0.025 with a 95% bootstrap confidence interval between 0.023 and 0.032.     

Uniform consistency rate of kNN regression estimation for functional time series data

In this paper, we investigate the k-nearest neighbours (kNN) estimation of nonparametric regression model for strong mixing functional time series data. More precisely, we establish the uniform almost complete convergence rate of the kNN estimator under some mild conditions. Furthermore, a simulation study and an empirical application to the real data analysis of sea surface temperature (SST) are carried out to illustrate the finite sample performances and the usefulness of the kNN approach.     

我国中性财政政策选择解析

从一国经济的可持续发展来看,积极财政政策的实施只能是阶段性、暂时性的,随着一国经济形势的发展变化应适时适度做出相应调整,才能更加科学地调控宏观经济布局和结构,使其沿着健康、稳定的发展运行轨道前进。伴随着我国积极财政政策的连续实行,经济增长加速效应突出,国民经济领域产生了许多结构性的问题和矛盾,这迫使我国财政政策的选择有必要由扩张性向中性转移。把握积极财政政策向中性的财政政策逐步过渡的“火候”,就要充分适应经济形势的不断变化,在调控目标、调控方式、调控手段和方法组合上进行适时调整,采用更为适合我国国情的科学的宏观调控财政手段。     

中国生育率研究方法:30年回眸

改革开放30年是我国人口学及人口研究迅速成长的30年。生育率研究方法从一个侧面反映出改革开放以来我国人口学研究方法的发展。中国的生育率研究方法既有从西方引进的各种生育率指标和模型,也有中国学者为了适应自己的需要而改进和创建的方法和模型。笔者从生育率度量指标和生育率模型两个方面总结我国生育率研究方法的应用及变化。对在中国生育率研究中所使用的主要方法进行回顾并对这些方法对我国生育率研究的贡献进行总结。     

中小型出口企业汇率风险管理研究

汇率变化始终影响着出口企业的经营与发展,以中小企业面临的汇率风险为切入点,阐述了其面临的主要风险是交易风险、会计风险和经营风险,并指出其汇率风险管理存在的问题：汇率风险意识淡薄、汇率风险管理机制缺失、银行业务有限、政府服务滞后等。面对日益增大的外汇风险,从企业自身、银行和政府三个层面提出了中小型出口企业汇率风险的防范与控制措施：重视汇率风险管理,不断提升产品核心竞争力;强化汇率风险意识,建立严格高效的内部控制制度;培养风险管理人才,健全风险管理体系;积极利用多种金融衍生工具规避风险;提高防御汇率风险的水平;依赖银行积极参与合作、政府保驾护航,实现稳健经营、健康发展。     

基于调研数据的总和生育率发展趋势及影响因素分析——来自湖北鄂州、黄石、仙桃的调查数据

文章基于5490份有效问卷的调查数据对湖北省总和生育率（TFR）进行分析。结论表明,自1985年以来年龄别生育率下降主要原因是计生政策严格控制生育数量,而非生育行为的推迟。TFR呈现先快速下降后缓慢上升的趋势,其变化与高生育水平育龄妇女占比无关。与政策生育率变化有关。通过对湖北省总出生人数进行估算和分析,结论表明1985—2008年总和生育率对总出生人数的影响程度要大于高生育水平育龄妇女占比的影响;外推预测表明2009～2014年出生人数趋势稳定,2015年以后呈下降趋势。利用Logit模型对实际生育水平的影响因素进行分析,发现有显著影响的因素为：受访者文化程度、户口性质、出生年代、工作状态、丈夫工作状态、放宽的计生政策和奖励少生的计生政策。     

中国城镇居民家庭储蓄水平队列效应分析

利用中国家庭收入调查（ CHIP）数据对城镇居民家庭的储蓄率进行了队列效应的实证研究。分析结果表明,属于不同队列的城镇家庭在储蓄水平上都呈现出相似的“U”型年龄分布,即中年家庭（40－50岁）储蓄率低,年轻家庭（20－40岁）和退休家庭储蓄率较高,这一现象与其他国家的实证研究结果有显著不同。本文认为,中国城镇居民储蓄率的“U”型年龄分布主要是由人口与经济的高速增长带来的：人口高速增长带来的队列规模效应使得面对更大竞争压力的年轻人口储蓄率较高,而经济水平持续增长带来的消费水平增长预期使得接近退休家庭储蓄水平重新上升。     

完善我国个人所得税制度的思考

费用扣除不合理,税率结构不科学,税收征管不力等是我国个人所得税制度存在的主要问题。应明确个税的税种归属,实行综合所得税制,调整税率结构,建立起有利于援助弱势群体的负所得税制度。     

Social time preference revisited

The article reconsiders the implications of the choice of pure social time preference for intergenerational equity in the presence of a time-consistent utilitarian social welfare criterion. The analytic framework is a setting with overlapping generations, lifetime uncertainty, population growth and technical progress. The analysis identifies upper and lower bounds for the feasible range of social discount rates and draws a corresponding distinction between “gerontocratic” and “Stalinist” optimal plans. The paper corrects a number of inaccurate propositions in a related earlier contribution by Marini and Scaramozzino (2000) to this journal.

A lost family-planning regime in eighteenth-century Ceylon

Based on Dutch colonial registers (thombos), this paper reconstructs fertility for two districts in Ceylon, 1756–68. It overcomes challenges in data quality by establishing the outer bounds of plausible estimates in a series of scenarios. Among these, total fertility rates (TFRs) averaged 5.5 in one district, but only 2.7 in the other. These figures exclude the victims of infanticide, a custom noted in European travelogues between about 1660 and 1820. Sex ratios among children differed depending on the number of older siblings, and overall, 27?per cent of girls are missing in one district and 57?per cent in the other. There was little significant variation either in the TFR or the sex ratio by socio-economic status, suggesting that poverty was not a key factor in motivating infanticides. Instead, we argue that at least parts of Ceylon had a forward-looking culture of family planning in the eighteenth century, which was lost in subsequent decades.