The Spatial Dimension of Segregation: A Case Study in Four French Urban Areas, 1990-1999

The aim of this paper is to analyze the intra-urban spatial segregation in terms of socio-professional categories in four French urban areas: Paris, Lyon, Bordeaux and Dijon. Two questions are investigated. First, how does spatial segregation vary across the four urban poles? Second, what are the spatial patterns of segregation within each urban pole? In order to answer these questions, we compute spatial global segregation indices for socio-professional categories in each urban area, together with entropy indices, which are local segregation indices that reflect the diversity within each unit and that can be mapped to show the spatial variations of segregation among the units of the four urban poles. The results highlight the self-segregation of the managers, the specific features of Paris and the complex spatial distribution of segregation.segregation, French urban areas, entropy index

THE SPATIAL DIMENSION OF SEGREGATION - A CASE STUDY IN FOUR FRENCH URBAN AREAS, 1990-1999 *

Over the post-war period, urban growth has exhibited complex spatial patterns including both population spread and employment suburbanization from the central city towards the suburbs, both in US and European metropolitan areas. An important literature, based on North-American metropolitan areas, has also highlighted the strong link existing between this process of suburbanization and the reinforcement of socio-spatial segregation against poor populations living in the central cities (Kain, 1992; Ihlandfeldt and Sjoquist, 1998). On the contrary, European cities do not usually follow this pattern: populations with high income remain localized in and near the city center while urban sprawl mainly concerns households with modest incomes. While the intensity and characteristics of spatial segregation has been extensively documented for US urban areas (Cutler and Glaeser, 1997) and mainly concerns segregation along the ethnic dimension (Taeuber and Taeuber, 1965; Massey and Denton, 1993), studies investigating the specificities of the segregation phenomenon in European cities in general, and French cities in particular, remain scarce (Rhein, 1998; Guermond and Lajoie, 1999; Préteceille, 2001). In this context, the aim of this paper is to analyze the intra-urban spatial segregration in terms of nationality, employment, socio-professional categories and income in four French urban poles: Paris, Lyon, Bordeaux and Dijon. More precisely, we are interested in answering the following questions. First, how does spatial segregation vary for these different measures and across the four urban poles? Second, what are the spatial patterns of segregation within each urban pole? In order to answer these questions, two steps are necessary. The first step involves computing global segregation indices for the different variables and urban poles. In particular, we focus on the Duncan and Duncan’s (1955) segregation and dissimilarity indices and their spatial versions (Wong, 1993), White’s (1983) index and Gini’s measure. Since these measures are global, the second step consists in identifying the spatial patterns involved. In that purpose, we compute entropy indices, which are local segregation indices that reflect the diversity within each unit and that can be mapped to show the spatial variations of segregation among the units of the four urban poles. The paper is organized as follows. First, we discuss the measures of spatial segregation used in this paper. Then we present the study areas, the data and the spatial weight matrix used to perform the analysis. The empirical results are divided in two parts: first, we compute global measures of spatial segregation for nationality, employment, socio-professional categories and income for our four urban poles and second, we display the local spatial segregation indices.

Segregação urbana: abordagem dos Índices sociais globais e locais

Understanding the phenomenon of segregation is essential to urban planning. The spatial indices of segregation are metrics that allow the identification of the spatial patterns of segregation of different population groups and their spatial variation within the city. In this article, global spatial and spatial segregation indexes were applied to the city of Marília-SP. The analysis of the local indexes revealed that the segregation of Marília can no longer be classified with classic center-periphery pattern. Although low-income groups are concentrated in the peripheries (south and northeast), Marília presents a pattern of differentiated macro segregation, with the consolidation of the sector that goes from the historical center to the east, in which high income population is grouped

Measuring Segregation Patterns and Change: a Co-Location Quotient Approach

There are many segregation measures introduced and utilized in geographic research up to this date. Because residential segregation can be defined in more than one way the measure’s formulation is dependent on the particular definition the researcher is trying to reflect. Another distinctive feature of the quantitative exploration of segregation is the role of geographic scale. In contrast, global indices focus on overall level of spatial separation of population in the urban area while local indices assume that the index magnitude varies from place to place across the city. The main purpose of this study is to introduce a new measure of segregation that focuses on the lack of interactions of the population groups and to explore its properties. The proposed measure is a modified co-location quotient (CLQ) that was originally applied to point data as a measure of spatial association between two categorical variables. The first part of this dissertation introduces two versions of modified CLQ that are applicable to categories of areally aggregated population. One is the global measure that captures the overall exposure of one population group given the presence of another group. The local version of the measure describes levels of exposure for every single spatial unit. Both, global and local quotients have two basic specifications – two-group CLQ and same-group CLQ. Each variant of the measure allows the option to include the neighborhood size in computation, which theoretically defines the space within which people have the possibility for interaction. The use of CLQ in the proposed mathematical configuration expands the discussion of dimensions of segregation by suggesting the connection between different dimensions that are covered by co-location measure. Using publicly available data from U.S. Census Bureau on racial composition of population CLQs were computed for thirty urban areas, where twenty nine are metro areas and one is Washington D.C. The basic units of analysis are census tracts and block groups that contain aggregated population counts. Three decennial releases are used: 1990, 2000 and 2010. The results suggest an overall, but uneven, increase in the exposure of white people in given urban areas. Patterns of concentration for white people remained stable over the time span. But the concentration of black people shows a substantial decrease indicating an increasing exposure of blacks in the global sense. Conversely, same-group CLQs for whites and for blacks indicate unequal experiences for these two population groups in America. Additionally, various visualization techniques related to co-location measure were explored. The pointillist approach, suggested in this study, is found to be particularly effective technique for displaying CLQ results compared to widely utilized choropleth mapping

Residential sorting across Auckland neighbourhoods

This paper addresses the extent to which people in Auckland exhibit residential location patterns that differ between groups, i.e. the extent to which they are spatially sorted. To measure patterns of residential location, the paper uses the index of segregation, an isolation index, Gini coefficients, Ellison & Glaeser and Maurel & Sédillot concentration measures, Moran’s I and Getis and Ord’s G*. Results are presented based on a classification of the population in different ways: ethnicity, income, education, age and country of birth. Both city-wide and local measures are considered. We find that ethnic-based sorting is the strongest indicator of residential sorting patterns, but soring by income, education and age is also present. Sorting by income and qualifications is strongest at the top and, to lesser extent, at the bottom of the income and qualifications range. Age segregation is most pronounced for older residents. Clustering is strongest within a range of up to one kilometre and declines significantly over greater distances. Local analysis by means of Getis and Ord’s G* calculations suggest significant ethnic clustering. Apart from Maori and Pacific Islanders, ethnic groups tend to locate way from each other, as confirmed with cross-Moran’s I calculations. When considering interactions between ethnicity and income we find that the location of ethnicity income subgroups is more strongly related to neighbourhood income

Segregation measures and spatial autocorrelation - Location patterns of immigrant minorities in the Barcelona Region

Given the important growth of immigrants in Spain it would be interesting to study its distribution throughout the urban area. Statistics suggest different large traditional indices allowing to quantify the segregation of minority population groups. Segregation can be measured from the different points of view and a new segregation perspective can be obtained by the utilisation of innovative indices including spatial statistics elements, as well as local indicators of spatial association (LISA). Through the application of these tools on the Barcelona and its metropolitan region case, its utilities in the analysis of resident segregation in a town are shown and segregation patterns are found out. The results point out that the segregation differs depending on the observed group. The combination of all these measures represents a useful proceeding in the analysis of the distribution of immigrants in the urban zones and its convenience extends to the different areas like sociology, economics, city planning or housing policies.

Urban Segregation: Global and Local Indices Approach

The understanding of the segregation phenomenon is essential to urban planning. Spatial Segregation indices are metrics which allow the identification of spatial patterns of segregation of different population groups and their spatial variation within the city. In this paper, global and local spatial indices of urban segregation were applied to the city of Marília-SP.  Local indices revealed that the segregation in Marilia can no longer be described using the classic pattern of centre-periphery. Despite the concentration of low income groups in the peripheral rings (in particular in the south and northeast zones of the city), a different macro segregation pattern can be observed. This pattern is characterized by the consolidation of the area of the city starting from the historical center towards the East area, in which the high-income population is concentrated. The research has also identified a high degree of segregation (isolation) of high-income groups in the East areas (horizontal gated communities) and low-income in the South area (low income informal settlements and communities), result that was reinforced by the insignificant index of exposition between these two groups in the south zone of the city.O entendimento do fenômeno da segregação é essencial ao planejamento urbano. Os índices espaciais de segregação são métricas que permitem identificar os padrões espaciais de segregação de diferentes grupos populacionais e sua variação espacial dentro da cidade. Neste artigo, índices espaciais globais e locais de segregação espacial foram aplicados à cidade de Marília-SP. A análise dos índices locais revelou que a segregação de Marília não pode mais ser classificada com padrão clássico centro-periferia. Ainda que grupos de baixa renda se concentrem nas periferias (zonas sul e nordeste), Marília apresenta um padrão de macro segregação diferenciado, com a consolidação do setor que vai do centro histórico à zona leste, no qual população de alta renda está agrupada. O estudo também revelou um alto grau de segregação (isolamento) da população de alta renda na zona leste (condomínios fechados) e de baixa renda na zona sul (favelas e conjuntos habitacionais), reforçados pelo índice insignificante de exposição entre os grupos opostos na zona sul da cidade

Segregación residencial y vivienda adecuada en los migrantes de Bolivia y Perú en Córdoba, Argentina

In a large part of Latin America, residential segregation has been examined almost exclusively from a socioeconomic perspective, with an ethnic approach far less common. The aim of this article is to analyze segregation of Bolivian and Peruvian migrants residing in the city of Córdoba and its association with access to adequate housing, based on data from the 2010 Census. Both groups are segregated and in deficient residential conditions. Although the most segregated group does not present the worst residential indicators, it is a paradox which underscores the complex relationship between segregation and access to adequate housingEn gran parte de América Latina la segregación residencial ha sido abordada casi exclusivamente desde una perspectiva socioeconómica, siendo mucho menos frecuente su abordaje étnico. El objetivo de este trabajo es analizar la segregación de los migrantes bolivianos y peruanos que residen en la ciudad de Córdoba y su vinculación con el acceso a una vivienda adecuada, a partir de datos del Censo de 2010. Ambos grupos se encuentran segregados y en condiciones residenciales deficientes. Aunque el colectivo más segregado no presenta los peores indicadores habitacionales, es una paradoja que evidencia la compleja relación entre segregación y acceso a una vivienda adecuadaFil: Molinatti, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; ArgentinaFil: Pelaez, Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; Argentin

Multidimensional Urban Segregation - Toward A Neural Network Measure

We introduce a multidimensional, neural-network approach to reveal and measure urban segregation phenomena, based on the Self-Organizing Map algorithm (SOM). The multidimensionality of SOM allows one to apprehend a large number of variables simultaneously, defined on census or other types of statistical blocks, and to perform clustering along them. Levels of segregation are then measured through correlations between distances on the neural network and distances on the actual geographical map. Further, the stochasticity of SOM enables one to quantify levels of heterogeneity across census blocks. We illustrate this new method on data available for the city of Paris.Comment: NCAA S.I. WSOM+ 201