A Surface-Based Approach to Measuring Spatial Segregation

Quantitative indices of residential segregation have been with us for half a century, but suffer significant limitations. While useful for comparison among regions, summary indices fail to reveal spatial aspects of segregation. Such measures generally consider only the population mix within zones, not between them. Zone boundaries are treated as impenetrable barriers to interaction between population subgroups, so that measurement of segregation is constrained by the zoning system, which bears no necessary relation to interaction among population subgroups. A segregation measurement approach less constrained by the chosen zoning system, which enables visualization of segregation levels at the local scale and accounts for the spatial dimension of segregation, is required. We propose a kernel density estimation approach to model spatial aspects of segregation. This provides an explicitly geographical framework for modeling and visualizing local spatial segregation. The density estimation approach lends itself to development of an index of spatial segregation with the advantage of functional compatibility with the most widely used index of segregation (the dissimilarity index D ). We provide a short review of the literature on measuring segregation, briefly describe the kernel density estimation method, and illustrate how the method can be used for measuring segregation. Examples using a simulated landscape and two empirical cases in Washington, DC and Philadelphia, PA are presented.     

Measuring the Scale of Segregation Using k‐Nearest Neighbor Aggregates

Nearly all segregation measures use some form of administrative unit (usually tracts in the United States) as the base for the calculation of segregation indices, and most of the commonly used measures are aspatial. The spatial measures that have been proposed are often not easily computed, although there have been significant advances in the past decade. We provide a measure that is individually based (either persons or very small administrative units) and a technique for constructing neighborhoods that does not require administrative units. We show that the spatial distribution of different population groups within an urban area can be efficiently analyzed with segregation measures that use population count‐based definitions of neighborhood scale. We provide a variant of a k‐nearest neighbor approach and a statistic spatial isolation and a methodology (EquiPop) to map, graph, and evaluate the likelihood of individuals meeting other similar race individuals or of meeting individuals of a different ethnicity. The usefulness of this approach is demonstrated in an application of the method to data for Los Angeles and three metropolitan areas in Sweden. This comparative approach is important as we wish to show how the technique can be used across different cultural contexts. The analysis shows how the scale (very small neighborhoods, larger communities, or cities) influences the segregation outcomes. Even if microscale segregation is strong, there may still be much more mixing at macroscales.     

SPATIAL DEPENDENCY OF SEGREGATION INDICES

A few researchers have mentioned the scale sensitivity of segregation index, D. In this paper, I discuss analytically and empirically why using large enumeration areal units usually results in low segregation measures, and using small areal units produces relatively high segregation measures. The discussion is also applicable to the multi-group variant of D. A major finding is that if people of the same ethnic groups are positively spatially auto-correlated, increasing the size of areal units of analysis may not lower D initially, because only people of the same group are added. But enlarging the areal units subsequently may include population of other ethnic groups, and therefore could lower D. However, if the boundaries of the larger enumeration units are drawn to include only population of the same group, then D will not change significantly. Both the spatial autocorrelation of ethnic group population and zonal pattern are critical factors in determining the scale sensitivity of D.     

Ethnic segregation in England's schools

We document ethnic segregation in secondary schools in England in 2001 in order to contribute to the debate on the degree of ethnic group social integration. We use indices of dissimilarity and isolation to compare the patterns of segregation across nine ethnic groups. We find that levels of ethnic segregation in England's schools are high, with considerable variation both across LEAs and across different minority ethnic groups. By combining the two indices we are able to identify areas of particular concern as scoring highly on both. For pupils of South Asian origin, these include the locations of the severe disorders in the summer of 2001. Finally, we show that ethnic segregation is only weakly related to income segregation.     

Changing Ethnic Segregation and Housing Disadvantage in Dundee

Abstract

Dundee has a small black and minority ethnic (BME) population, which has been neglected by previous research, as have BME populations in small towns and cities generally. As in other British cities, the residential locations of the main BME groups are distinct from that of the white population. After briefly reviewing the history of settlement in Dundee, this paper examines the extent to which patterns of ethnic segregation have changed between 1991 and 2001. Some moves towards dispersal and suburbanisation are identified but there are important contrasts between different BME groups. The implications of segregation for housing availability are assessed through Census of Population data. The hypothesis is posed that the consequences of segregation for housing disadvantage are greater in small cities such as Dundee.     

Racial Segregation and Class in a Liberal Metropolis

As overt racial discrimination lessens and the social and economic status of minorities rises, segregation by class should become more and segregation by race less prominent. This hypothesis is tested via several structural and spatial measures of segregation, for class and for race separately and simultaneously. Even in the ostensibly liberal Seattle, race is found to remain vastly stronger than class for blacks, and even somewhat stronger for Asians.     

Spatial Empirics for Economic Growth and Convergence

This paper suggests some new empirical strategies for analyzing the evolution of regional income distributions over time and space. These approaches are based on extensions to the classical Markov transition matrices that allow for a more comprehensive analysis of the geographical dimensions of the transitional dynamics. This is achieved by integrating some recently developed local spatial statistics within a Markov framework. Insights to not only the frequency with which one economy may transition across different classes in the income distribution, but also how those transitions may or may not be spatially dependent are provided by these new measures. A number of indices are suggested as ways to characterize the space‐time dynamics and are illustrated in a case study of U. S. regional income dynamics over the 1929–1994 period.     

The Vic Model: From school redistribution to xenophobic voting

In 1997, the authorities of Vic, a municipality with one of the highest immigration rates in Spain, implemented a programme called the Vic Model, which was a plan for the geographical redistribution or desegregation of immigrant students. The aim of the programme was to avoid the concentration or segregation of immigrants, which was defined as a problem, and to thereby dilute ethnic and cultural differences. According to scientific research, implementing such measures intensifies xenophobic and discriminatory attitudes among local populations. To analyse the relationship between this redistribution approach, which views immigrants as a burden, and xenophobic voting, we first document the examined case and then perform a quantitative analysis at both the regional and local levels by using demographic and electoral data. The results show an association between the assisted dissemination of immigrants throughout the municipality and an increase in xenophobic voting.     

SPACE AND THE MEASUREMENT OF INCOME SEGREGATION

ABSTRACT.  This paper proposes a new spatial ordering index that that can be used to quantify the dependence of a given pattern of income segregation on the spatial arrangement of neighborhoods. Unlike other spatial measures of income segregation proposed in the literature, the spatial ordering index is less sensitive to the presence of outliers, satisfies the "principle of transfers," and is flexible enough to quantify a variety of spatial patterns of segregation. The index can be interpreted in terms of the ratio of two covariances. Properties of the proposed measure are demonstrated using an example from the city of Baltimore, Maryland.     

Multiple Contexts as Cross-classified Models: The Labor Vote in the British General Election of 1992

Voters make their decisions in social and geographical contexts that can be seen as different levels in an overall data structure. Increasingly these structures are being analyzed by multilevel models, but this approach has so far been limited to structures that are strictly hierarchical. This paper outlines the approach of cross-classified multilevel models in which units at lower levels in the structure can be nested in more than one higher-level unit simultaneously. An appropriate modeling framework is outlined, models are specified, and particular attention is paid to efficient computation. The approach is illustrated through a cross-classified logit analysis of Labor versus Conservative support for a nationally representative sample of voting behavior for the 1992 British General Election. The data is structured so that individual voters at level 1 are nested within constituencies at level 2 which are cross-classified by geographical and functional regionalizations at level 3. A conclusion discusses the general utility of a cross-classified approach to geographically based contextual research, while two technical appendices provide details on model estimation.     

UN NOUVEAU CADRE MÉTHO-DOLOGIQUE POUR L'ÉTUDE DE LA SÉGRÉGATION RÉSIDENT1ELLE APPLIQUÉÀ MONTRÉAL (1931-71)

Les études sur la ségrégation résidentielle, basée sur l' ethnie, utilisent généralement un cadre méthodologique comprenant des indices de ségrégation dont l' insensibilityéà certaines transformations importantes de l' espace ethnique peut être démontrée. De plus, la forte redondance de ces indices vient encore réduire la portée de leur utilisation. De nouveaux indices sont donc proposés lesquels, étant donné leur aspect complémentaire et non redondant, seront susceptibles de produire une analyse plus complète du phénomène de ségrégation résidentielle. En guise ď illustration, les indices proposés ont été utilisés dans une analyse de l' évolution de la ségrégation résidentielle ayant affecté certains groupes ethniques, à Montréal, durant la période 1931–1971.
The methodological approach in residential segregation studies is based essentially on the use of indexes such as D (dissimilarity index) and G (Gin; index). However, these are redundant indexes that measure only one aspect of segregation, its intensity. This paper proposes a new set of non-redundant indexes that give better results as shown by their use in analysing the ethnic space of Montreal between 1931 and 1971     

ACCOUNTING FOR NEIGHBORING EFFECTS IN MEASURES OF SPATIAL CONCENTRATION*

ABSTRACT A common problem with spatial economic concentration measures based on areal data (e.g., Gini, Herfindhal, entropy, and Ellison‐Glaeser indices) is accounting for the position of regions in space. While they purport to measure spatial clustering, these statistics are confined to calculations within individual areal units. They are insensitive to the proximity of regions or to neighboring effects. Clearly, since spillovers do not recognize areal units, economic clusters may cross regional boundaries. Yet with current measures, any industrial agglomeration that traverses boundaries will be chopped into two or more pieces. Activity in adjacent spatial units is treated in exactly the same way as activity in far‐flung, nonadjacent areas. This paper shows how popular measures of spatial concentration relying on areal data can be modified to account for neighboring effects. With a U.S. application, we also demonstrate that the new instruments we propose are easy to implement and can be valuable in regional analysis.     

政区·官署·省会——清代省名含义辨析

清代地方高层政区是否有正式名称,公文中存在的大量省名的含义是什么,这是两个相互关联的问题。本文首先梳理了清代各个时期法典的记载,发现这些法典均将地方高层政区称之为"省",说明"省"就是清代地方高层政区的正式名称。其次,指出公文中存在的形形色色省名,清人已经说明这是对省级行政机构(衙门)的称呼。第三,说明清人也习惯将省城简称为省。清代将地方高层政区、省级行政机构、省会均称之为"省"。     

Geographies of family formations: spatial differences and gender cultures in Britain

The significance of national differences in family formations has been addressed through the social policy debate over women's position in different welfare state regimes. However, the nature and effects of sub–national family geographies remains under–researched. In this paper we use census mapping to describe regional and local differences in partnering and parenting within Britain. We develop an index of the 'Motherhood Employment Effect' to indicate different geographical levels of adherence to the 'traditional' male breadwinner/female homemaker family, and use a 'Family Conventionality' index to describe geographical differences in the social evaluation of marriage. The geography of family formations thus described does not follow the better known 'north–south' or 'urban–rural' geographies of economic performance and prosperity. We use the example of Lancashire and Yorkshire to explore further the socio–economic associations of this family geography, employing additional indicators of 'household conventionality' and 'family restructuring'. Finally, we speculate as to how this relatively unfamiliar family geography may be related to the existence of regional gender cultures, and briefly outline some implications for social policy.     

A NOTE ON NEIGHBORHOOD SIZE AND THE MEASUREMENT OF SEGREGATION INDICES*

This note examines neighborhood segregation measures with respect to size and validity. Conventional measures, while related to within-neighborhood homogeneity, are not necessarily related to neighborhood size. An empirical test examines racial segregation for Baltimore in 1970 and 1980 using both census tract and specially formulated neighborhood aggregates. For both years, and for all measures of segregation, the values and trends are essentially unchanged by the level of aggregation.     

Dimensions and dynamics of residential segregation by income in urban Canada, 1991–1996

This paper examines the trends in residential segregation by income (post-transfer, pretax income) in the thirty-nine largest Canadian urban areas between 1991 and 1996. The study is motivated by the relative lack of attention paid to residential segregation by income in the Canadian context and by conceptual arguments linking compromised life chances and increased social tensions for the populations of highly segregated cities. We investigated several dimensions of segregation using five different measures (we focus on three of these here given the correlation structure of the measures) to examine changes in segregation between 1991 and 1996, a period characterised by economic recession, cutbacks in social programs and a widening of inequality in market incomes at the national scale. Overall, income segregation increased in most urban areas across all dimensions of segregation during the time period, with particularly high degrees of segregation observed in prairie cities (Winnipeg, Saskatoon and Regina). Of the three largest metropolitan areas (Vancouver, Toronto and Montréal), Montréal was the most consistently segregated. We also find that increases in spatial separation and spatial concentration by income occurred despite the fact that at the national scale, the tax and transfer system appeared to be adequately redressing a rise in inequality in labour and market incomes (as demonstrated by the lack of change in post-transfer national income inequality measures during a period when inequality in market and labour incomes rose sharply). This implies that the lived experience of changes in income distribution are unlikely fully captured by aspatial, national-scale measures and that intra-urban measures with a spatial dimension are an important indicators of inequality in Canadian society.     

区域文化产业竞争力评价分析:基于VRIO模型的修正

近年来国内关于区域文化产业竞争力评价的研究成果层出不穷,然而由于文化产业竞争力的抽象性,学界对其概念的界定和影响因素重要程度的理解不同,关于其评价原则及具体标准难以形成一致观点。本文在对现有评价体系进行总结和评述的基础上,依据VRIO模型,构建了一套新的区域文化产业竞争力评价体系。该评价体系有效突出文化产业的发展潜力、创新性和稀缺性等评价时的特性;突出了文化产业的社会属性和可持续发展能力;明确了众多影响要素的层次关系和作用结构;强化了评价体系的可操作性,以试图更加客观、全面地反映我国文化产业的发展情况。     

广州市外来人口居住隔离及影响因素研究

利用广州市人口普查街道(部分居委会)数据总结1990-2000年外来人口居住隔离的时空特征:隔离程度呈增加趋势,核心和外围区隔离程度及变化差异大,散点状为主的空间模式,并呈现异质性和非稳定性的社会特征。通过典型社区问卷访谈,对比外来人口与户籍低收入人口,建构影响因素的逻辑回归(Logistic regression)模型,显示户籍的属地差别是产生隔离的根本原因,与户籍属地管理相关的劳动力市场分割和住房政策共同构成了排斥的制度环境,限制了外来人口的住房选择,把其推向低端私人租房市场。在有限的居住选择下,交通和经济等个体择居要素影响了隔离空间的分布和社会特征,以城中村为代表低端私人租房来源的布局特征决定并固化了隔离空间的分布模式。     

Clarifying the Standard Deviational Ellipse

For a set of geographical units in the Cartesian coordinate system, the locus of the standard deviation of the x coordinates of the set forms a closed curve as the system is rotated about the origin. This curve, often referred to as “standard deviational ellipse” (SDE), is not in fact an ellipse. The actual shape of the curve has remained unclear since the issue was mentioned initially by Lefever in 1926. In the present paper this closed curve, referred to as “standard deviation curve” (SDC), is clarified mathematically, and some of its applications in spatial analysis are discussed. The shape of SDC changes from a single circle to double circles when the distribution of the set of geographical units changes from an even condition to a straight line. The shape of SDC is determined explicitly by the ratio of its minor axis to its major axis. This ratio, therefore, is a useful index to show to what extent the distribution of a set of geographical units is circular, or linear. In addition, the size and radius of SDC can be used to indicate the distribution density of geographical units. The major axis of SDC, whose angle is determined explicitly for the first time, indicates the major orientation of geographical units. A program has been developed to apply SDC to spatial analysis (mean center, major orientation, distribution density, circular condition, etc.). The program is available from jx_gong@hotmail.com . It is written in the MapBasic language, and runs under MapInfo.