城市聚集经济理论及其演进

城市聚集经济理论的发展大致经历了三个阶段。早期文献对城市聚集经济的研究乃基于马歇尔的内部经济和外部经济概念,将城市聚集经济分为三个不同的层次类型。自20世纪60年代后期起,区域经济学者开始将城市聚集经济融合到城市经济模型中去,试图在城市经济模型中体现出聚集经济的作用。自90年代以来,区域经济学中研究城市聚集经济的微观机理的文献逐渐增多起来。此类文献从各自不同的视角,试图为城市聚集经济提供一个微观基础,揭示其微观机理。纵观城市聚集经济理论的发展脉络,迄今为止尚未出现一种具有微观基础的整体性的理论。     

户籍制度背景下农民工与城市移民的储蓄率差异

本文基于异质性主体的三期世代交叠模型,从理论上刻画了作为短期移民的农民工和农村进城永久移民的储蓄率差异。由于户籍差异,农民工在城市中的经济状况欠佳且无健全的社会保障,为了支付老年时期的生活成本,他们在城市工作期间的储蓄率会高于实现了户籍身份转换的永久移民。进一步地,本文使用CHIP2013年数据对农民工和永久移民的储蓄率差异进行了RIF回归分解。总分解结果表明,要素效应缩小了农民工与永久移民的储蓄率差异,而结构效应却会扩大两者储蓄率的差异;构成分解结果进一步表明,户主的人力资本特征差异会缩小两者储蓄率的差距,而家庭收入的差异扩大了两者储蓄率的差距。因此,深化户籍制度改革将使更多的农民工成为城市永久居民,这能够增加他们在城市的消费,从而起到城镇化带动消费的作用。另外,储蓄行为是移民经济社会融合的一种表现形式,户籍身份转换带来的消费提升也有助于促进农民工在城市的融合。     

从冲突到融合——“知识型准移民”的路径选择

通过对湖南多城市的探索性问卷调查,研究城市准移民群体中规模庞大、亟待关注,却被忽略的"知识型准移民"青年的社会适应与城市融合问题。从道德社会学视角作了探讨。     

聚集经济与区域经济发展

长期以来,聚集经济一直被认为是城市经济的本质特征,各种要素在一定空间范围内的高度聚集形成了城市和城市经济.但是随着区域经济发展以及区域空间结构的不断演化,我们越来越清晰地认识到聚集经济在区域经济发展中的地位和作用.文章将在具体分析聚集经济形态和本质的基础上,从理论和实证的角度来说明聚集经济与区域经济发展的关系.     

城市经济聚集理论的演变与发展

城市经济发展的最初动因是源自于技术进步基础上的生产和消费的聚集。由聚集而形成规模报酬递增和外部经济造成了产业规模的不断扩张和结构升级,城市经济因此不断发展,城市功能也在日益增强。但聚集并不是无限制的堆积,受规模积累效益递减规律的影响,城市聚集的过程中也不断地进行着扩散,通过扩散寻求更高质量层次的聚集。两者的交替衍变是一种动态的辨证过程,城市经济正是在这种交替衍变过程中往前发展。文章通过城市经济发展理论的历史回顾,对城市经济发展中的聚集理论进行了综合介绍和评析。     

城市化与城乡收入——城乡分割制度改革的逻辑与对策

本文采取了"刘易斯+马克思+斯密"的视角,基于中国城乡分割制度变迁以及城乡移民与城市居民之间劳动分工关系的特征事实,提出理论假说:城乡移民对城乡收入的影响受到城乡制度分割程度的调节。来自1995—2008年中国215个地级市的面板数据实证分析量化了该理论假说:城市收入对城乡移民的弹性受到城乡分割显著的负向调节,农村收入对城乡移民的弹性受到城乡分割显著的正向调节。在低程度的城乡分割区间,城乡移民有利于城市收入而不利于农村收入;在高程度的城乡分割区间,城乡移民有利于农村收入而不利于城市收入;在城乡分割程度居中的区间,城乡移民既有利于城市收入又有利于农村收入。因此,户籍等城乡分割制度无法激励相容地自发破除,改革须依赖于利益中性的顶层设计。     

农村—城市移民率的变动与中国城市化的关系

在我国的经济发展过程中,城市化水平不断提高,并伴随有大量的农村人口向城市转移。本文通过构建一个理论分析框架,在城市化水平与农村—城市移民率的变动之间建立一个模型,发现在农村—城市移民率和城市化水平、农村人口与总人口自然增长率之间存在着联系。通过城市化数据分析我国的农村—城市移民率的变化情况,并应用城市化的logistic方程对城市化水平以及农村—城市移民率进行进一步的估计,最后预测它们未来的发展趋势。     

聚集经济、市场拥挤效应与城市规模

本文利用2003—2012年中国285个地级及以上城市的面板数据,在新经济地理学的理论框架下,运用动态面板数据模型的估计方法进行了实证研究。结果表明,中国城市规模主要受到聚集经济的影响,市场拥挤效应不显著,由于聚集经济的存在,城市规模具有自我膨胀的趋势。不同等级城市规模的研究也印证了以上的结论,并且,城市规模越大,聚集经济效应就越大,城市自我膨胀的趋势也就越显著。     

国家大学科技园区域融合度测算及路径选择

国家大学科技园是实现区域产学研结合的关键平台之一,但相比国家高新区,大学科技园的区域融合优势亟待发挥。在国家大学科技园非均衡布局基础上,援引我国15个副省级城市的38家国家大学科技园数据,从资源集聚融合、园区互动融合、经济链接融合3个方面,选取20个相对指标,比较国家大学科技园的区域融合度,并运用K均值聚类法划分区域融合路径模式。结果表明,不同城市间的国家大学科技园融合度呈现出明显差异,融合结构呈现非均衡性;国家大学科技园的区域融合优势与城市经济规模并无正相关性。     

对城市规模理论的再认识

最优城市规模问题是城市化过程中一个重要的理论与现实问题,本文在分析了城市规模涵义的基础上,提出了区位优势与城市最优聚集规模的关系,随后分析了最优城市规模理论和最优城市规模理论的困境,城市规模的发展是一个动态均衡过程,适度城市规模网络结构是对最优城市规模理论的批判和修正。     

The effects of immigration restriction laws on immigrant segregation in the early twentieth century U.S.

Several immigration restriction laws, passed in the background of anti-immigration populism in the early 1920s, put an end to the period of “open borders” in the U.S. In this paper, I use the linked county sample in the early twentieth century to examine how immigration restriction laws led to different trends in segregation across groups. Difference-in-difference estimations show that all immigrant groups followed similar trends in segregation before the passage of immigration laws; afterwards, segregation among immigrants from more restricted countries declined relative to segregation among immigrants from less restricted countries. I then construct linked census samples at the individual level, and study mechanisms behind de-segregation. I find two possible mechanisms: (a) limitations on new arrivals; (b) selection on return migration. Further analyses suggest that de-segregation might not benefit immigrants’ socioeconomic assimilation.     

SEGREGATION IN THE AUSTRALIAN LABOUR MARKET*

An important measure of the success of immigration is the assimilation of immigrants into the labour force of the host country. This criterion is important from both the perspective of immigrants themselves and that of the host country. Conversely, concentration of migrants in a few sectors is undesirable because of its adverse socio‐economic consequences. Since the pattern of distribution of migrant employment influences the structure and outcomes in the labour market in various ways, it attracts public, academic and policymakers’ attention. The present paper employs various numerical measures to estimate the degree of immigrant segregation across occupations and industries in Australia. The results indicate that the occupational distribution of immigrants is very similar to the proportion of native workers employed in the various occupations. This similarity also characterises the industrial distribution of immigrant employment. Thus, contrary to popular perception and findings for the United States, evidence from the Australian labour market does not indicate the existence of widespread immigrant segregation.     

Some Reflections on the Spatial Dimensions of Occupational Segregation

This paper considers the role that urban spatial structure may play in the process of occupational segregation, and argues that neoclassical economic models of urban employment and residential location decisions have not considered the relationship between gender-based labor market status and space. The paper provides a critical feminist perspective on how conventional urban models have been used to explain patterns of segregation, and suggests reasons for limitations in existing theoretical and empirical analysis. It also explores ways in which economists can draw on work in other disciplines to develop fuller and more useful models of the relationship between urban spatial structure and occupational segregation.     

Migration,Friendship Ties,and Cultural Assimilation

We study immigrant assimilation by analyzing whether friendship with natives is a measure of cultural assimilation, and by investigating the formation of social ties. Using the German Socio‐Economic Panel, we find that immigrants with a German friend are more similar to natives than those without German friends, along several important dimensions, including concerns about the economy, an interest in politics, and a host of policy issues. Turning to friendship acquisition, we find that becoming employed, time spent in the host country, the birth of a child, residential mobility, and additional education acquired in the host country are significant drivers of social network variation.     

地区金融发展与经济增长的典型相关分析

从金融发展理论产生的背景和所使用的分析工具上,寻找金融发展理论与实证研究产生分歧的原因。首先,从发达国家的利益出发,用根据发达国家的经济条件和经验得出来的西方主流经济理论来研究发展中国家的金融发展问题是其主要原因;其次,有关金融发展计量分析工具没有考虑金融风险因素。根据中国国情,从金融生态的角度,引入典型相关模型,探讨金融发展与经济增长的互动关系,建立了分析金融发展与经济增长互动关系的指标体系。     

The transferability of human capital: some empirical evidence for West Germany

One of the most important topics in the current debate on immigration policy is whether receiving countries should make immigration conditional upon the achievement of formal education by the would-be immigrant in the source country. The answer to this question depends, among other factors, on the transferability of schooling and professional education from the sending to the receiving region. The paper uses German household data of 1978, 1982 and 1989 to evaluate to what extent formal education acquired by the main immigrant groups (Italians, Yugoslavs, Turks) in their countries of origin leads to earnings advantages in Germany. Consistent with earlier research, an assimilation effect is found. The results also show that schooling and professional education lead to earnings advantages. However, income differences between the three immigrant groups can only partially be explained by differences in schooling and professional education. It is found that nonobservable characteristics such as motivation, talent and the dynamics of the migratory chain also play a major role. The results indicate that Germany and other European receiving countries could, in theory, increase their welfare by integrating qualitative restrictions along educational characteristics in their immigration policies. The size of the increase, however, would be limited because of the importance of nonobservable characteristics and declining transferability of human capital as the source composition of immigrants shifts towards less developed countries.     

劳动生产率:关联与差异-基于GWR模型的分析

运用2007年286个城市的数据和局部线性空间模型,本文对中国城市劳动生产率的空间模式和影响因素进行了分析.研究发现,中国286个城市劳动生产率的空间模式表现出以下特点:总体来看,我国城市劳动生产率由东至西呈现出递减趋势,而区域劳动生产率在东部和西部表现出了比较显著的集聚特征-即两个区域的城市劳动生产率分别表现出各自的区域匀质性,但是中部地区城市间劳动生产率的分布没有表现出类似的匀质性.     

Is Racial Exclusion Gendered? The Role of Residential Segregation in the Employment Status of Black Women and Men in the US

This paper explores one angle of the race/gender/class intersection by examining the effect of residential segregation on black women and men's employment status in the US. Do the exclusionary mechanisms embedded in racially-based residential segregation affect black women and men's economic outcomes similarly, or are their employment outcomes differentiated by their different gender statuses? This paper lays out a theoretical framework for understanding the role residential segregation may play in shaping black men and women's labor market outcomes, outlining key mechanisms that link residential segregation to labor market inequality, highlighting the ways in which many of these mechanisms are gendered as well as racialized. This paper also offers an analytic design to test the hypotheses developed in this exploration.     

INEQUALITY AND THE MEASUREMENT OF RESIDENTIAL SEGREGATION BY INCOME IN AMERICAN NEIGHBORHOODS

American metropolitan areas have experienced rising residential segregation by income since 1970. One potential explanation for this change is growing income inequality. However, measures of residential sorting are typically mechanically related to the income distribution, making it difficult to identify the impact of inequality on residential choice. This paper presents a measure of residential segregation by income, the Centile Gap Index (CGI), which is based on income percentiles. Using the CGI, I find that a one standard deviation increase in income inequality raises residential income segregation by 0.4–0.9 standard deviations. Inequality at the top of the distribution is associated with more segregation of the rich, while inequality at the bottom and declines in labor demand for less-skilled men are associated with residential isolation of the poor. Inequality can fully explain the rise in income segregation between 1970 and 2000.     

Firm heterogeneity and immigrant wage assimilation

This article investigates the role of job mobility in immigrant wage assimilation. I use longitudinal linked employer–employee data for Portugal to estimate the immigrant wage catch-up in log wage regressions with both individual and firm fixed effects. I show that moving to firms with higher wage premiums accounts for approximately 30% of the immigrant wage catch-up in the first years.