Gravity Parameter Estimation

The question of whether ordinary least-squares (OLS) regression provides unbiased estimates for parameters of the gravity model is investigated. Holding attractiveness constant and looking only at the location of destinations, OLS is shown to give unbiased estimates if underlying behavior conforms to the gravity hypothesis. Johnston's conjectures on this are examined and found to explain only partially observed variations in distance exponents. Allowing attractiveness to vary, spatial autocorrelation in attractiveness is shown to lead to bias in OLS estimation due to misspecification, even where behavior conforms to the gravity hypothesis. Deterministic and stochastic illustrations are provided.     

环境公正视角下空气污染和死亡人数的空间分析及关系研究——以河北省为例

基于空气污染的环境公正研究在国际上受到较多关注,但在发展中国家、尤其是中国,相关研究较为缺乏。本文使用2010年河北省人口普查和空气质量数据,采用空间分析、描述性统计以及空间回归模型等方法对基于乡镇街道层面的空气污染和死亡人数的空间分布、社会分布及其关系进行研究。结果表明,河北省空气污染和死亡人数在城市和农村地区存在显著差异;基于乡镇街道层面,河北省的婴儿（1岁及以下）、老年人（60岁及以上）、失业者和省外农村流动人口更多地居住在空气污染比较严重的地区;婴儿、老年人、使用固体燃料或住房无洗澡设施的家庭户聚集的乡镇街道其死亡人数较多;空气污染与死亡人数之间存在显著的正相关。本研究旨在促进对中国环境公正与健康不平等的理解和认识,为发展更为公平、有效的环境健康政策提供科学依据。     

中国城乡居民收入差距的省区间比较分析

中国城乡居民收入差距问题早已存在,但目前对城乡居民收入差距的研究大都是从全国的角度出发,从省区的角度进行的定量对比研究很少。而现实中省区间的城乡居民收入差距却存在着明显的差别,这种差别对于我们进行具体的成因分析以及因地制宜地制定城乡居民收入政策具有重要的意义。为此,本文利用1978- 2000年各省区城乡居民收入统计资料,采用回归分析和相关性分析的方法,从空间分布和时间序列变化两个方面对省区间的城乡居民收入差距进行了初步研究,揭示了城乡居民收入差距由东向西逐渐扩大的空间布局以及时间序列变化上的不同步性,同时,还对形成这种空间不平衡和时间变化不同步的原因进行了初步探讨,为进一步的成因分析及城乡政策的制定奠定基础。     

Spurios Spatial Regression: Some Monte Carlo Results with a Spatial Unit Root and Spatial Cointegration

In this paper I introduce the concepts of spatial unit roots and spatial cointegration, and via Monte-Carlo simulation I illustrate their implications for spatial regression. It is shown that spatial unit roots lead to spurious (spatial) regression, as in the well-known case involving time-series. Spatial cointegration is similar to its time-series counterpart, although I demonstrate that OLS estimation of spatial error-correction models is not consistent.     

A Nonparametric Analysis of Employment Density in a Polycentric City

Nonparametric estimation procedures offer distinct advantages in modeling polycentric cities because they are flexible enough to account for functional form misspecification and incorrect subcenter sites. This paper presents locally weighted (LW) regression estimates of employment density in suburban Chicago. LW regression estimates are more accurate than OLS regression and capture the effects of missing variables. The results demonstrate that Chicago is indeed a polycentric city: although the traditional city center continues to affect employment density patterns in the suburbs, local peaks have developed around secondary employment centers.     

Identifying the Impacts of Land-Use Spatial Patterns on Street-Network Accessibility Using Geospatial Methods

While the land use-street network nexus is well acknowledged, evidence for the one-way impacts of land-use patterns on street accessibility is still inadequate. The measurements of land-use patterns and street accessibility lack systematic knowledge. Their empirical correlations also lack geographical variability, constraining site-specific land-use practices. Therefore, this study overcame the aforementioned limitations by examining the two-level spatial models to formulate accessibility-oriented land plans, using a well-developed Chinese city as an example. Firstly, two landscape metrics—Euclidean Nearest-Neighbor Distance (ENN) and Similarity Index (SIMI)—were used to quantify the intra- and inter-land-use configurations, respectively. Both city-level and local accessibility were measured using spatial design network analysis. Performing both ordinary least squares (OLS) and geographically weighted regression (GWR) models, results identified the statistically significant effects of inter-land-use patterns on two-level street accessibility. An exception was that land-use configurations within residential and industrial regions were irrelevant to street accessibility. We also found GWR was a better-fitting model than OLS when estimating locally-varied accessibility, suggesting hierarchical multiscale land-use planning. Overall, locally heterogeneous evidence in this study can substantialize land use-street network interactions and support the decision-making and implementation of place-specific accessibility-oriented land use.     

OLS ESTIMATION AND THE t TEST REVISITED IN RANK‐SIZE RULE REGRESSION*

ABSTRACT The rank‐size rule and Zipf's law for city sizes have been traditionally examined by means of OLS estimation and the t test. This paper studies the accurate and approximate properties of the OLS estimator and obtains the distribution of the t statistic under the assumption of Zipf's law (i.e., Pareto distribution). Indeed, we show that the t statistic explodes asymptotically even under the null, indicating that a mechanical application of the t test yields a serious type I error. To overcome this problem, critical regions of the t test are constructed to test the Zipf's law. Using these corrected critical regions, we can conclude that our results are in favor of the Zipf's law for many more countries than in the previous researches such as Rosen and Resnick (1980) or Soo (2005) . By using the same database as that used in Soo (2005) , we demonstrate that the Zipf law is rejected for only one of 24 countries under our test whereas it is rejected for 23 of 24 countries under the usual t test. We also propose a more efficient estimation procedure and provide empirical applications of the theory for some countries.     

中国女性农民工务工活跃度研究——基于全国29省份调查数据与陕西省实证研究

基于全国范围内(除京沪港澳台地区)女性农民工外出务工调查数据,提出女性农民工务工活跃度新概念,并将该概念分解为四个活跃度因子:务工距离、务工时间、务工地点数以及务工频数,用层次分析法得出各因子的权重并计算各省市区的活跃度。引入对应各省市区农民人均纯收入进行回归分析,与多项式模型拟合较好,活跃度随农民人均纯收入的减小而有增大的趋势。分别对四个活跃度因子的地理空间分布进行研究,运用聚类分析法进一步探究务工活跃度结合农民人均纯收入在地理空间上的分布特征,并在全国范围内划分出7个区域类型。最后以陕西省为例,用Logistic回归模型得出女性农民工的个人、家庭及其他因素对务工活跃度有较大影响。     

Industry Characteristics Linked to Establishment Concentrations in Nonmetropolitan Areas

In this paper we investigate industry characteristics associated with the clustering of establishments in three-digit SIC manufacturing industries in nonmetropolitan areas. The dispersion parameter k of the negative binomial distribution is selected as the measure of industry spatial concentration. Associations between industry characteristics and spatial concentration are investigated using OLS regression analysis. Our findings indicate that the spatial clustering of establishments is positively related to industry average establishment size, reliance on natural resource inputs, labor intensity, cost shares of professional and technical employees, and cost shares of low-skilled workers. Agglomeration is negatively related to multiplant structure, employment in precision production, and reliance on local product and input markets.     

A comment on Steele’s (2010) “radiocarbon dates as data: quantitative strategies for estimating colonization front speeds and event densities”

We show that Steele’s (2010) criticisms of Hamilton and Buchanan (2007) and Buchanan et al. (2008) do not hold water and demonstrate that his re-analyses of Hamilton and Buchanan’s (2007) and Buchanan et al'.s (2008) datasets are flawed. In the process, we highlight some important issues for researchers interested in using radiocarbon dates to reconstruct population movements and demography. Most notably, we explain why OLS regression is preferable to RMA regression when estimating diffusion velocity, and demonstrate that the summed probability distributions yielded by CalPal are more reliable as guides to past demographic change than those produced by Calib and OxCal.     

Research briefing

Although pharmacies play an important role in providing information and advice on health issues to lower income people in developing countries, the distribution of urban pharmacies is not balanced with respect to population distribution in some of the districts of Istanbul. This situation can severely limit the accessibility of pharmacy services to the people with lower socio‐economic background. A multiple regression analysis is used in order to find out the factors which affect the spatial distribution of pharmacies in Istanbul. The number of pharmacies in the districts considered is taken as the dependent variable and the number of hospital beds, physicians, population, employment, income, number of educated people and distance to the CBD are taken as independent variables. According to the results, the population of the districts and the number of educated people, physicians and hospital beds are the most important factors affecting the location of pharmacies in Istanbul. The other variables are not found significant in affecting the location of pharmacies at the metropolitan level. Suggestions are made for better distribution of pharmacies and for further research.     

基于土地利用数据和夜间灯光数据的人口空间化模型对比分析——以黄河三角洲高效生态经济区为例

人口统计数据空间化是解决统计数据与自然要素数据融合分析的有效途径。随着RS和GIS技术的发展,人口空间化方法推陈出新,但不同的方法各有优缺点,方法选择和精度保证是两个重要的问题。本文以黄河三角洲高效生态经济区2010年县(市、区)单元人口统计信息为案例,分别基于土地利用数据和夜间灯光数据建立1km栅格的人口空间化模型,再分别以县(市、区)和乡(镇、街道办)为验证单元,比较两种方法模拟人口分布的优缺点。结果表明,基于土地利用数据的人口空间化模型整体优于基于夜间灯光数据的人口空间化模型,且前者更适合于模拟人口总数居中的县(市、区),后者在人口密度梯度较大的城镇边缘有更好的模拟效果,在人口较少的地区二者的模拟效果均不太理想。本研究能够为获取高精度的区域人口空间化模型提供参考。     

Political Economy of Income Distribution: A Comparative Study of Taiwan and Mexico

Both Taiwan and Mexico have experienced remarkable economic growth since the 1960s. Taiwan demonstrates that higher income level can be accompanied by falling income inequalities. However, unlike Taiwan, the course of economic growth in Mexico has left the country with a very unequal distribution of income. This paper compares the government policies of income distribution in Mexico and Taiwan and identifies the factors contributing to the success of Taiwan and to the highly uneven income distribution in Mexico. The paper concludes that market-oriented growth does not automatically reduce inequality or poverty. The prospects for better income equity and sustainable economic development would be greatly enhanced through implementation of policies aimed at redistributing land and skills, facilitating small enterprises, and increasing domestic saving.     

L'identification des zones calmes et un diagnostic d’équité environnementale à Montréal

Quiet urban areas are places with low noise levels that can help people to support physical and mental wellness. This paper has two objectives: to identify quiet urban areas in Montreal and to check for the presence of environmental inequities in access to such areas for vulnerable groups (children, older people, low‐income individuals, and visible minorities). Using a GIS‐based methodology, 2,282 quiet urban areas were identified in Montreal. The results of a mixed effects logistic regression model analysis showed that there are no major inequities in access to quiet urban areas for the population groups studied. The analysis did, however, revealed substantial spatial disparities in terms of the distribution of quiet urban areas across the boroughs and municipalities examined.     

Does Income Distribution Affect U.S. State Economic Growth?*

Abstract. Numerous models propose an income‐distribution/growth linkage, but the empirical evidence is ambiguous and depends on the regression approach. Mixed findings are not unexpected if there are differing short‐ and long‐term responses. Approaches utilizing cross‐sectional variation primarily reflect long‐run effects, whereas those using time‐series variation primarily reveal short‐run effects. This study reconciles these issues using U.S. state data. After allowing for short‐ and long‐run responses and for separate effects between the tails and middle of the distribution, the consistent pattern is the middle‐class share and overall inequality are positively related to long‐run growth. However, the short‐run income‐distribution response is less clear.     

THE DAY AFTER THE DISASTER: FORCED MIGRATION AND INCOME LOSS AFTER HURRICANES KATRINA AND RITA

A model of post‐disaster migration responses and income consequences poses that damage severity and individual resilience affect moving decisions. Forced moves are linked to little resilience relative to damage incurred and post‐move income reductions. The empirical analysis analyzes households affected by hurricanes Katrina and Rita. Using American Community Survey data, unobserved heterogeneous income damages are framed as treatment, with the moving decision being the treatment decision. An endogenous switching regression addresses self‐selection issues. The results suggest that movers encountered double victimization: (1) they were forced to move and their income declined; (2) low‐income households were more severely affected than the average.     

新中国收入分配制度的演变及绩效分析

新中国收入分配制度和政策的演变大致经历了两个时期:一是从1949年建国到1978年中共十一届三中全会前的29年,这个时期制度演变的趋势是生产资料的公有化和生活资料占有的平均化;二是1978年中共十一届三中全会至2006年中共十六届五中全会的28年,这个时期制度演变的趋势是生产资料所有制的多样化和生活资料占有的差距扩大。新中国收入分配变化的轨迹经历了一个由旧中国收入水平极低、分配极不平等通过革命手段达到过度平均,然后又由这种过度平均通过改革走向拉开收入差距的“否定之否定”过程。收入的平均程度主要受到中国共产党的经济和社会发展观念、战略、政策变化以及不同时期积累与消费关系变动的制约。     

HAPPY IN THE HOOD? THE IMPACT OF RESIDENTIAL SEGREGATION ON SELF‐REPORTED HAPPINESS

Previous research consistently finds that racially based residential segregation is associated with poor economic, health, and social outcomes. The purpose of this paper is to explore the relationship between residential segregation and self‐reported happiness. Using panel data from the National Survey of Families and Households (NSFH), we begin by estimating ordinary least squares (OLS) regressions of happiness on a measure of MSA‐level segregation, controlling for a rich set of individual, neighborhood, regional, and state characteristics. The OLS results suggest that increased segregation is associated with a reduction in happiness among blacks. To deal more appropriately with the potential endogeneity of location choice, we extend the methodology to fully exploit the panel structure of the NSFH and incorporate individual fixed effects into the happiness equation. Contrary to the OLS results, our fixed effects estimates imply that blacks are happier in more segregated metropolitan areas. The paper discusses the implications of these results within the context of current integration policies.     

City–suburban electoral polarization in Great Britain, 1950–2001

The degree to which residents of British inner cities and suburbs have diverged in their voting behaviour over the post-war period is analysed in this article. Examining aggregate election results by constituency, it is demonstrated that residents of inner cities and suburbs are indeed polarizing in their electoral choices. OLS regression analysis is conducted using constituency-level data to determine the relevance of intra-urban differences for understanding geographic variation in the vote in relation to those for region, size of conurbation and urban–rural distinctions. Results show that urban place of residence is particularly important for understanding the shifting geography of Conservative support. The implications of this research for electoral change in Britain are discussed.