A play-the-winner-type urn design with reduced variability

We propose a new adaptive allocation rule, the drop-the-loser, that randomizes subjects in the course of a trial comparing treatments with dichotomous outcomes. The rule tends to assign more patients to better treatments with the same limiting proportion as the randomized play-the-winner rule. The new design has significantly less variable allocation proportion than the randomized play-the-winner rule. Decrease in variability translates into a gain in statistical power. For some values of success probabilities the drop-the-loser rule has a double advantage over conventional equal allocation in that it has better power and assigns more subjects to the better treatment. Acknowledgments. I thank Stephen Durham, the associate editor, and the referees for their helpful suggestions.     

Family and sex-specific U.S. immigration from Europe, 1870–1910: A panel data study of rates and composition

This paper develops and estimates models of family and sex-specific emigration, as well as the sex composition of this emigration, from 12 European source countries to the U.S. for the period 1870–1910. The models are based on the distinction between economic migrants (males, single females, and some married females) and tied or trailing migrants (females) and are estimated with panel data, including data that relate to the occupational/industrial structure of male and female economic activity in source countries. Hausman-Taylor instrumental variable estimates suggest that although both males and females responded to labor-market signals, males were more responsive than females to per capita GDP differences. Moreover, compared to the rest of Europe, Ireland, and Scandinavia were the sources of many young, single male, and female migrants, who responded strongly to gaps in economic opportunities. In fact, much of the European response to such gaps appears to be due to migrants from Ireland and Scandinavia. Females tended to originate in English-speaking countries and countries that were agriculturally oriented. Service and manufacturing jobs in source countries discouraged the migration of females relative to males. Males tended to follow recent migrants more than females, but females responded more to long-term influences as measured by stocks of migrants from their source countries who had previously settled in the U.S. Countries with high birth rates had relatively fewer female emigrants, whereas those with high rates of natural increase 20 years earlier experienced relatively more male emigration. Intact families, other family members (including family-strategy male migrants and trailing female migrants), and single males and females responded strongly to economic incentives, but the singles were most responsive followed by family-strategy males.     

Competition as a track for preventing illegal immigration

Rich countries often face sizeable illegal migration. This paper suggests that these countries would use the financial aid which they give to the source countries as an instrument to prevent illegal immigration. The core of this policy is to allow the source countries to compete for the pre-determined aid, which would be distributed according to the cross-proportion of the apprehended illegal aliens. Moreover, we show that it may be beneficial for the rich country to split the source countries into competing pairs rather than allowing all of them to compete jointly. The rich country has basically two policy means: funds allocated to strengthening its border control; and the foreign aid given to the source countries. The multi-country general equilibrium model presented shows how the rich country, by choosing an appropriate mix of these two policy means, can minimize the number of illegal immigrants subject to its budget constrain.Received: 15 August 2002, Accepted: 21 January 2004, JEL Classification: F22Nava Kahana, Tikva Lecker: The authors are grateful to two anonymous referees for their valuable comments.     

三峡库区发展高效生态农业的途径和对策

论述高效生态农业在三峡库区建设和移民安置中的战略意义。从三峡库区实际出发，分析库区高效生态农业发展的现状和难点、机遇和方向。指出高效生态农业的发展不仅能给库区移民带来显著的经济效益，促进库区农业、环境、社会的持续发展，而且能确保三峡工程建设顺利进行和长治久安。并针对目前库区农业存在的问题，提出了库区农业高效生态化及产业化的发展对策。     

移民积分制的全球实践及其启示

移民积分制是一种挑选移民主要是高技能人才的重要政策工具,在一些具有移民传统的发达国家和地区广泛使用,并受到越来越多的国家关注。目前,实施移民积分制的国家,一类为实施积分制,另一类为实施类积分制,这两类的典型国家分别为加拿大和德国。通过概述加拿大积分制和德国类积分制的实践,深入分析了移民积分制的实施前提、主要特征,剖析了实施移民积分制的优点和不足,继而对实施和调整移民积分制的整体框架进行了反思与归纳。我国当前仍处在经济社会快速发展的阶段,迫切需要各类科技人才,必须加快移民积分制的实施,但在实施过程中,应该注意对实施对象的范围做出严格限定,所制定的积分制要有利于满足高层次科技创新创业人才以多种方式来中国发展的需求,并可采取国家、省级两级积分体系。     

China's One‐Child Policy: Some Unintended Consequences

This paper gives a brief overview of China's family planning policy which, although recently relaxed, still controls a large swath of the population. Unofficially known as the ‘one‐child policy’, it resulted from the social strife of the 1970s coupled with a Malthusian pessimism concerning the capability of the still largely closed and isolated Chinese economy to care for itself. We discuss the motivations for the policy, the unfortunate demographic future that it will create, and some policy reforms that can be undertaken today.     

INTERNATIONAL MIGRATION: A CASE AGAINST BUILDING EVER‐HIGHER FENCES

International migration, seen as a powerful force of truly global character that is shaping today's socio‐economic reality, is a highly controversial and politicised issue. This paper explores its ramifications in the context of a growing backlash against immigration across the rich world. Specifically, it argues that the free flow of people – like the free movement of goods and capital – is beneficial to developed and developing economies alike and, in doing so, shows how migration produces win–win outcomes. Thus the study, while admitting that inflows of foreign‐born workers pose challenges and entail trade‐offs, makes a case for the liberalisation of immigration policies. The paper deepens our understanding of the issues at hand and constitutes a voice in favour of liberal‐policy choices.     

Mustn't Grumble: Immigration,Health and Health Service Use in the UK and Germany*

A rise in population caused by increased immigration is sometimes accompanied by concerns that the increase in population puts additional or differential pressure on welfare services, which might affect the net fiscal contribution of immigrants. The UK and Germany have experienced significant increases in immigration in recent years and this study uses longitudinal data from both countries to examine whether immigrants differ in their use of health services from native-born individuals on arrival and over time. While immigrants to Germany, but not the UK, are more likely to self-report poor health than the native-born population, the samples of immigrants use hospital and GP services at broadly the same rate as the native-born populations in both countries. Controls for observed and unobserved differences between immigrants and native-born sample populations make little difference to these broad findings.     

Effects of Free Trade on Women and Immigrants: CAFTA and the Rural Dominican Republic

We construct a disaggregated rural economywide model with a focus on gender and immigration as well as on the allocation of time to wage work, household production activities, and housework (reproduction). We use this model to simulate the impacts of the Dominican Republic-Central American Free Trade Agreement (DR-CAFTA) on rural incomes and welfare in the Dominican Republic. We find that elimination of agricultural import tariffs hurts both agricultural and non-agricultural households, via adverse factor-market effects, but impacts vary substantially by workers’ gender and country of origin. Females and Haitian immigrants tend to fare better than Dominican males, and there are ramifications for both market and non-market activities.     

关于加快推进城镇化的几个问题

城镇化的核心问题是农村人口转移,加快推进城镇化进程,是促进城乡经济社会全面发展,逐步实现现代化的过程,“城镇化”并不是“小城镇化”,而是包括大中小城市和小城镇,大中小城市和小城镇各有自己的的优势和局限,不能相互替代,可行的选择是大中小城市和小城镇协调发展,推进城镇化应打破行政区划,形成以大城市为中心的城镇体系,大中城市是第三产业发展的主要载体,在大中城市发展过程中,需要妥善处理“城中村”问题,提高征用土地的补偿标准,保障“失土农民”的利益,农民工对城市发展做出了重要贡献,是城市人口扩张的重要来源之一,必须公正对待农民工,推进城镇化绝不意味着可以放弃和忽视农村,而应当进一步关注和支持农村经济社会发展,应当充分利用推进城镇化这个宝贵机会,对农村面貌特别是农业产业布局进行革命性的改造,在建设现代化城市的同时建设现代化农村。