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Recent advances in quantitative tools for examining urban morphology enable the development of morphometrics that can characterize the size, shape, and placement of buildings; the relationships between them; and their association with broader patterns of development. Although these methods have the potential to provide substantial insight into the ways in which neighborhood morphology shapes the socioeconomic and demographic characteristics of neighborhoods and communities, this question is largely unexplored. Using building footprints in five of the ten largest U.S. metropolitan areas (Atlanta, Boston, Chicago, Houston, and Los Angeles) and the open-source R package, foot, we examine how neighborhood morphology differs across U.S. metropolitan areas and across the urban-exurban landscape. Principal components analysis, unsupervised classification (K-means), and Ordinary Least Squares regression analysis are used to develop a morphological typology of neighborhoods and to examine its association with the spatial, socioeconomic, and demographic characteristics of census tracts. Our findings illustrate substantial variation in the morphology of neighborhoods, both across the five metropolitan areas as well as between central cities, suburbs, and the urban fringe within each metropolitan area. We identify five different types of neighborhoods indicative of different stages of development and distributed unevenly across the urban landscape: these include low-density neighborhoods on the urban fringe; mixed use and high-density residential areas in central cities; and uniform residential neighborhoods in suburban cities. Results from regression analysis illustrate that the prevalence of each of these forms is closely associated with variation in socioeconomic and demographic characteristics such as population density, the prevalence of multifamily housing, and income, race/ethnicity, homeownership, and commuting by car. We conclude by discussing the implications of our findings and suggesting avenues for future research on neighborhood morphology, including ways that it might provide insight into issues such as zoning and land use, housing policy, and residential segregation. [ABSTRACT FROM AUTHOR]

It has become increasingly important in spatial equity studies to understand activity spaces – where people conduct regular out-of-home activities. Big data can advance the identification of activity spaces and the understanding of spatial equity. Using the Los Angeles metropolitan area for the case study, this paper employs geotagged Twitter data to delineate activity spaces with two spatial measures: first, the average distance between users' home location and activity locations; and second, the area covered between home and activity locations. The paper also finds significant relationship between the spatial measures of activity spaces and neighborhood spatial and socioeconomic characteristics. This research enriches the literature that aims to address spatial equity in activity spaces and demonstrates the applicability of big data in urban socio-spatial research. [ABSTRACT FROM AUTHOR]

This paper studies how immigrant parents value education for their children in the United States when making residential decisions. Parent valuation of education is examined through the differential effects of school quality on the residential location choices of households with and without children. The analysis relies on data from the 2000 Census and focuses on the Los Angeles Metropolitan Area. The results suggest that immigrant parents place a positive weight on school quality when choosing residences. The weight assigned to school is positively associated with household income and householder's education. The paper further explores variation across immigrants to get at the potential economic mechanisms for differential valuation of school quality. Number of school-aged children in the household, selective migration, and potential returns to education may explain variation in the emphasis immigrant parents place on school quality in residential location choices. [ABSTRACT FROM AUTHOR]

This paper examines taxable sales in the Los Angeles and Miami metropolitan areas to find evidence of the short- and long-run effects of the Rodney King riots and Hurricane Andrew on their respective economies. The comparison of these two events shows that the King riots had a long-term negative effect on Los Angeles' economy while Hurricane Andrew had a short-term positive effect on the Miami economy. The paper also applies the contrasting experiences of Los Angeles and Miami to New Orleans following Hurricane Katrina. In some ways, Katrina is a hybrid of these two events since it combines elements of both a natural disaster and a social disaster. The paper examines how Katrina is similar to each of the previous incidents and how these similarities might affect the recovery of New Orleans following the storm. [ABSTRACT FROM AUTHOR]

Waterways and water bodies worldwide are impacted by anthropogenic litter (hereafter "litter" or "trash"), generated from nonpoint sources. This study analyzes litter loads across various land uses within two Los Angeles County watersheds: the Ballona Creek and the Los Angeles River. Our objective is to present a methodology to develop buildup and washoff parameters for densely populated urban areas, such as the coastal metropolitan area of Los Angeles, California. An assessment is also made to test how these model parameters perform when applied to another urbanized watershed with similar rainfall and climate patterns (i.e., the San Diego River Watershed in California). Using extensive litter collection data from small drainages (approximately 572 locations, each draining 0.05–8.5 ha), we estimate buildup and washoff model parameters. These parameters are used to simulate the buildup of litter and subsequent washoff (load) of litter in our selected watersheds. Simulated results are validated against observed data from different years in all three watersheds. To date, no study has used litter washoff data to develop these parameters for stormwater models and applied them on a regional scale. We compared linear and nonlinear power functions of litter buildup during interstorm periods. Although there were limited data to develop washoff parameters, an exponential washoff function was used and calibrated to the observed washoff. Generally, storm events with the greatest antecedent dry days had the largest litter loading. Buildup rates varied among land uses, and key calibration parameters included the maximum buildup, buildup rate constant, washoff exponent, and washoff coefficient. A parameter sensitivity analysis was conducted to reveal the washoff exponent as the most sensitive parameter. Annual litter loading estimates were 4.60 kg/ha for the Ballona Creek and 11.50 kg/ha for the Los Angeles River. Litter loading estimates for Ballona Creek were validated and calibrated to align with observed data from the Ballona Creek Trash Interceptor, resulting in an annual washoff load of 2.1 kg/ha. The estimated annual litter loading for the Lower San Diego River was 2.15 kg/ha falling between the mean (0.77 kg/ha) and the maximum (3.56 kg/ha) observed values. When applying model parameters from one watershed to another, models require extensive calibration and validation data, as extrapolating data between watersheds can introduce errors. Practical Applications: This research can inform stormwater modelers about the process for developing parameters to estimate water quality in numerical modeling software. We demonstrate how data from field sampling can be directly used to develop model parameters. Results show that with proper validation data, stormwater models can accurately simulate annual litter loads in modeled watersheds. Future studies can test model parameters in other urbanized watersheds to validate the potential for standardized buildup values. Field studies can be done in conjunction with the results from this survey to investigate and further validate litter loads mobilized by stormwater. This study highlights the need for long-term monitoring to improve and update models in the future. Although there is a risk of inaccurate results when extrapolating model parameters from one watershed to another, this research indicates the potential for developing buildup and washoff parameters that can be used as a starting point for parameter selection across urban watersheds. [ABSTRACT FROM AUTHOR]

This paper examines the role of selected institutional forms and formal initiatives (councils of governments and joint power authorities) as integrative functions among local governments of the metropolitan region. These sub-regional networks provide integrative functions and enjoy greater success in implementing regional projects than their regional counterparts. This paper draws lessons from different examples of initiatives in the Greater Los Angeles area. These associations may signal a shift to a governance paradigm where policy creation and implementation is less a product of top-down intentional design, as it is individual vision, initiative, and leadership at the local levels. [ABSTRACT FROM AUTHOR]

This paper first introduces the key players involved in the deployment of Intelligent Transportation Systems (ITS) technologies in the Los Angeles metropolitan area. The paper then reports the local deployment status of major Advanced Public Transportation Systems (APTS) projects, with a particular emphasis placed on the burgeoning Los Angeles Smart Shuttle Demonstration Project. In addition, the paper analyzes some technical, political, financial and other issues centering around the deployment of APTS technologies in the Los Angeles metropolitan area. [ABSTRACT FROM AUTHOR]

At the national level, the Asian American population has grown more than any other major race group. According to the 2010 Census, the Los Angeles metro area had 2,199,186 Asians, making it the home to the largest Asian population in the United States. Following close behind was the New York City metro area with 2,008,906 Asians. Over a quarter of the 14.7 million Asian Americans reside in either of the two greater metropolitan regions, where they comprise around a tenth of the total population in each metropolis. We begin with a brief historical overview of immigration legislation that has both invited and excluded Asian Americans, as a means of understanding how Asian Americans have been perceived over time. We will also compare some key characteristics of Asian American populations in Los Angeles County, New York City, the Balance of LA Combined Statistical Area (CSA) (excluding Los Angeles County), and the Balance of NYC CSA (excluding New York City), and the Balance of United States. The paper will cover: (1) demographic trends and patterns (2) economic status (3) political engagement and incorporation, and (4) residential settlement patterns. We close with a discussion of how these demographic changes have contributed to Asian Americans rapid social, economic, and political upward mobility in the last decade, at a time when the global restructuring of the economy has blurred nation-state boundaries that once existed and migration from Asia to the United States has become more complex, particularly over the past two decades. [ABSTRACT FROM AUTHOR]

Our paper addresses the complex role of Business Improvement Districts (BIDs) in current processes of inner-city restructuring and the function of BIDs in the implementation of new forms of social control in downtown areas. Our thesis is that, in the context of recent urban renaissance initiatives, BIDs are expanding their ‘clean and safe’ profile to be a much more comprehensive programme. Their goal is not only to produce safety and cleanliness in the urban environment but to influence the symbolic dimension of what the city is and for whom it is made. This implies indirect forms of governing the way in which the city is used, which go unnoticed if BIDs are identified solely as a tool to create ‘clean and safe’ public space. We will substantiate this claim with a case study on the current restructuring of downtown Los Angeles (L.A.). Since 1999, downtown L.A. has been profoundly ‘revitalized’ as a living and entertainment district for affluent residents. The nine BIDs covering the main parts of the downtown play an important role in making this gentrification happen by providing the appropriate context for restructuring. Beyond overt measures such as security forces or CCTV, the BIDs also have an important impact on the ‘geographical imagination’ (Harvey, 1973) of the city. The examples elucidate the anticipation of a broadening field of activity for BIDs, not only in securing an ‘urban renaissance’ but also in framing the way it is performed symbolically. [ABSTRACT FROM PUBLISHER]

This paper studies the effect of a newly completed highway extension on home prices in the surrounding area. We analyze non-linearities in both the effect of distance from the highway and the effect of time relative to the completion of the road segment. While previous studies of the effects of nearby amenities on property and land values have focused on either cross-sectional spatial or temporal patterns, the joint analysis of the two dimensions has not been thoroughly investigated. We use home sale data from a period of 11 years centered around the completion of a new highway extension in metropolitan Los Angeles. We combine a standard hedonic model with a spline regression technique to allow for non-linear variations of the effect along the temporal and spatial dimensions. Our empirical results show that the maximum home price appreciation caused by the new highway extension occurs at moderate distances from the highway after it is completed. Lower price increases for this period are observed for homes sold closer to the highway or much further away. This price pattern gradually fades away in the years following the construction completion. A similar, although weaker, price pattern is also observed in the first years of the construction period. There is no statistically significant distance dependency in the 2 years in our sample prior to the beginning of the construction. This indicates that the housing market is not fully efficient as the information about the impending construction of the highway is not immediately incorporated into sales prices. [ABSTRACT FROM AUTHOR]

This paper analyzes human-animal landscapes within an urban setting. I use a historical ecology approach to discuss the formation of (post)modern landscapes in the twenty-first century Los Angeles. The historical approach is necessary to make informed decisions for habitat restoration, and to map out human influences on natural ecosystems (Egan and Howell 2001). In the process I discuss strategies for a new urban wildlife theory. Conflicts and encounters between humans and non-humans can be more intense and controversial in a city. Because cities are usually seen as human-only landscapes, urban wildlife is more marginalized there than anywhere else. This is especially relevant in Los Angeles, a prime example of unchecked growth that brings more urbanites to the periphery and into contact with wild animals. For that reason I maintain that an urban setting is ideal for wildlife conservation and creating more egalitarian human-nonhuman relations and for breaching of traditional boundaries of exclusion. The definition of urban, in this paper, includes areas within city limits, as well as areas outside: suburbs or urban fringe. With growing urbanization and the spread of built-up areas all over the world, there remains no choice but to create more hospitable conditions for wildlife within the city, if we want to preserve the wellbeing of individual animals or entire species and ecosystems. I am interested in various qualities in urban landscapes that would create these conditions. [ABSTRACT FROM AUTHOR]

Metaphors are a powerful way of representing the complexities of the modern metropolis. Using the popular rhetoric that ''Los Angeles is the capital of the Third World'' the paper shows that the insights gained from exploring this metaphor are radically different from the modeling approaches popularized by the Chicago School. [ABSTRACT FROM AUTHOR]

Belowground urban stormwater networks (BUSNs) are critical for removing excess rainfall from impervious urban areas and preventing or mitigating urban flooding. However, available BUSN data are sparse, preventing the modeling and analysis of urban hydrologic processes at regional and larger scales. We propose a novel algorithm for estimating BUSNs by drawing on concepts from graph theory and existing, extensively available land surface data, such as street network, topography, and land use/land cover. First, we derive the causal relationships between the topology of BUSNs and urban surface features based on graph theory concepts. We then apply the causal relationships and estimate BUSNs using web-service data retrieval, spatial analysis, and high-performance computing techniques. Finally, we validate the derived BUSNs in the metropolitan areas of Los Angeles, Seattle, Houston, and Baltimore in the US, where real BUSN data are partly available to the public. Results show that our algorithm can effectively capture 59 %–76 % of the topology of real BUSN data, depending on the supporting data quality. This algorithm has promising potential to support large-scale urban hydrologic modeling and future urban drainage system planning. [ABSTRACT FROM AUTHOR]

We examine how the decay of high‐frequency amplitudes of Fourier spectra of strong earthquake ground acceleration (described in seismological literature by the slope parameter κ $\kappa $) depends on the soil and geological site conditions at the recording stations in the Los Angeles metropolitan area. Then, we introduce a Gedanken numerical experiment, in which we analyze nonlinear wave motion in shallow soil and show that it also leads to similar decay of the high‐frequency spectral amplitudes. The results of both of our studies are consistent with the interpretation that the decay of high‐frequency Fourier spectra of strong motion acceleration, described by κ $\kappa $, occurs at the recording site near the ground surface. [ABSTRACT FROM AUTHOR]

Abstract: The cultural industries have been solidly established in the contemporary economic development agenda. But the creative agenda and its accoutrements are often thought of under a large umbrella sometimes ignoring the composition of industries and occupations that comprise the cultural sector in various cities. In this paper, we look at the way in which cultural capital is distinctly place-specific. Unpacking the occupational and industrial makeup of the artistic and cultural sectors in Los Angeles and New York we study how their cultural capital is a function of each city’s unique advantages and skill needs rather than simply a product of “the arts”. We find that the cultural workers in each city work in remarkably different industries. We consider how the skill and industry composition that each city possesses informs unique development trajectories. More broadly we speculate how these nuances might explain the cultural distinction that each city possesses. [Copyright &y& Elsevier]

Access to parks and recreational facilities, as well as their quality, congestion, and affordability, relates to physical activity levels and, in turn, various health outcomes. Yet park and recreational resources are often insufficient and unevenly distributed within metropolitan regions. This paper documents and analyzes the allocation of federal, state, special district, municipal, and nonprofit resources to parks and recreation facilities across municipalities within the Los Angeles region. Results indicate that local funding for parks and recreation resources is highly uneven (from less than 1 to over 500 per capita annually). Because most park and recreation spending originates at the local level, fiscally healthier cities allocate more resources to these uses. State and nonprofits funds tend to favor middle-income communities and fail to equalize spending. Inner-ring suburbs with large minority populations, and low-income exurban communities are most likely to suffer from low expenditure. Federal devolution, increased localization of service provision, and limited intergovernmental transfers have resulted in large intrametropolitan disparities in the distribution of resources for parks and recreation, ultimately shaping the landscape of health risks for local populations. [ABSTRACT FROM AUTHOR]

A regulation banning new fast-food establishments for one year in Los Angeles, California, was passed unanimously by the city council in July 2008. It was motivated by health concerns and excessive obesity rates in South Los Angeles. However, it might not have had the impact that was intended. This paper reviews the empirical evidence for the regulation and whether it is likely to target the primary levers of obesity. We argue that the premises for the ban were questionable. For example, the density of fast-food chain restaurants per capita is actually higher in other parts of Los Angeles than in South LA. Other changes, such as menu calorie labeling, are likely to have a bigger impact on overweight and obesity. [ABSTRACT FROM AUTHOR]

We investigated the ozone pollution trend and its sensitivity to key precursors from 1990 to 2015 in the United States using long-term EPA Air Quality System (AQS) observations and mesoscale simulations. The modeling system, a coupled regional climate–air quality model (CWRF-CMAQ; Climate-Weather Research Forecast and the Community Multiscale Air Quality), captured well the summer surface ozone pollution during the past decades, having a mean slope of linear regression with AQS observations of ∼0.75. While the AQS network has limited spatial coverage and measures only a few key chemical species, CWRF-CMAQ provides comprehensive simulations to enable a more rigorous study of the change in ozone pollution and chemical sensitivity. Analysis of seasonal variations and diurnal cycle of ozone observations showed that peak ozone concentrations in the summer afternoon decreased ubiquitously across the United States, up to 0.5 ppbv yr -1 in major non-attainment areas such as Los Angeles, while concentrations at certain hours such as the early morning and late afternoon increased slightly. Consistent with the AQS observations, CMAQ simulated a similar decreasing trend of peak ozone concentrations in the afternoon, up to 0.4 ppbv yr -1 , and increasing ozone trends in the early morning and late afternoon. A monotonically decreasing trend (up to 0.5 ppbv yr -1) in the odd oxygen (Ox=O3+NO2) concentrations are simulated by CMAQ at all daytime hours. This result suggests that the increased ozone in the early morning and late afternoon was likely caused by reduced NO– O3 titration, driven by continuous anthropogenic NOx emission reductions in the past decades. Furthermore, the CMAQ simulations revealed a shift in chemical regimes of ozone photochemical production. From 1990 to 2015, surface ozone production in some metropolitan areas, such as Baltimore, has transited from a VOC-sensitive environment (>50 % probability) to a NOx -sensitive regime. Our results demonstrated that the long-term CWRF-CMAQ simulations can provide detailed information of the ozone chemistry evolution under a changing climate and may partially explain the US ozone pollution responses to regional and national regulations. [ABSTRACT FROM AUTHOR]

We introduce a mathematical framework that allows one to carry out multiscalar and multigroup spatial exploratory analysis across urban regions. By producing coefficients that integrate information across all scales and that are normalized with respect to theoretical maximally segregated configurations, this framework provides a practical and powerful tool for the comparative empirical analysis of urban segregation. We illustrate our method with a study of ethnic mixing in the Los Angeles metropolitan area. [ABSTRACT FROM AUTHOR]

The article reports on retail sales and store analysis in Los Angeles, Beverly Hills and Hollywood, California. Censuses from the years 1929, 1933 and 1935 included information from all three geographic regions, despite different populations and business prosperity. A chart is presented which tracks the total market share of sixteen regions within the entire Los Angeles market. Relative gains and losses in sales volume changes are presented. Additional analysis and charts seek to evaluate the changing patterns between downtown Los Angeles and the county as a whole, potentially suggesting a decentralized retail trade industry.

ABSTRACT In the wake of the U.S. housing crisis, what has happened to the substantial stock of foreclosed or real estate-owned (REO) properties is only beginning to be understood. The eventual outcomes of these properties are central to our understanding of the varied impacts of the foreclosure crisis, including its contribution to enduring and emerging patterns of uneven development. This article considers the scope and potential impacts of investor purchases of foreclosures in diverse neighborhoods in the Los Angeles region. Overall, findings suggest that very different patterns of investment emerged in the urban core, the postwar inner-ring suburbs, and the exurbs. In addition, investors' purchases and strategies varied significantly according to neighborhood racial composition and, to a much lesser extent, neighborhood socioeconomic characteristics. These patterns highlight two major issues: a sharp divide in investment between the relatively similar urban/inner-ring suburban core and the newer exurbs; and the enduring relationship between race and capital investment in neighborhoods in the wake of the housing crisis. [ABSTRACT FROM AUTHOR]

Major arts and cultural institutions have expanded their exhibits and programs to reflect society's growing diversity, but we know little about potential neighborhood disparities in arts participation within metropolitan areas and how it varies across institutions and different forms of engagement. Unlike membership, which tends to be 'market' driven, museum school tour programs often target underserved schools to engage diverse communities. We provide the first assessment to our knowledge of whether school tours provide a counterweight to more expensive forms of participation and whether ethnic-oriented institutions have been able to overcome the distance that often separates disadvantaged communities from institutions. Our analysis of participation rates for five major institutions in Los Angeles, California, indicates that, despite progress, barriers persist. Although affluent areas provide an important membership base, school tours offer a valuable tool for attracting traditional and ethnic-specific audiences and communities. The results support greater integration of city and cultural planning and suggest that institutions should redouble efforts to overcome sociocultural and geographic barriers. [ABSTRACT FROM AUTHOR]

What is the relationship between school segregation and neighborhood segregation across school districts in Los Angeles County, and are school district outcomes on reading and mathematics scores related to levels of school segregation across these districts? We compute segregation scores using US tract level data for 2000 and use reading and mathematics scores from California State tests. Data from the Los Angeles family and neighborhood survey are used to track individual residential changes and differences in the associated Woodcock Johnson scores. We show that there is a close link between levels of school segregation and neighborhood segregation and that many suburban school districts are relatively integrated across both neighborhoods and schools. When we examine average school district outcomes on reading and mathematics scores we do not find any relationship with levels of segregation. At the same time there is clear evidence of spatial sorting with poorer and lower scoring children moving into school districts (or zones with poorer achieving schools). The multi-level models of segregation and achievement show that the variance in achievement levels across districts is significantly greater than across schools within districts. [ABSTRACT FROM AUTHOR]

The existence and persistence of cities provide prima facie evidence of agglomeration economies, but do little to inform our understanding of the specific nature of forces that induce the concentration of economic activity, nor the spatial scale at which they occur. Though the theoretical literature on conceptualizes these forces without specific geographic scale, the empirical literature largely treats them as working mainly at the metropolitan level. We argue that agglomeration may work at different spatial scales. There is now extensive evidence that metropolitan areas are polycentric, with a significant portion of employment clustered in employment centers outside the CBD. This provides basic evidence of net agglomeration benefits at the sub-metropolitan level. We explore theories of agglomeration and consider how they may explain the presence, location, characteristics, and growth of employment centers. We illustrate the usefulness of exploring polycentricity with a case study of the Los Angeles region. Our understanding of agglomeration economies can be enriched by investigating the nature of employment centers and the forces that produce and sustain them. [ABSTRACT FROM AUTHOR]

Immigrants concentrate in particular lines of work. Most investigations of such employment niching have accented either the demand for labor in a limited set of mostly low-wage industries or the efficiency of immigrant networks in supplying that labor; space has taken a backseat or has been ignored. In contrast, this article's account of immigrant employment niching modulates insights built on social network theories with understandings derived from relative location. We do so by altering the thinking about employment niches as being metropolitan wide to considering them as local phenomena. Specifically, the analysis examines the intraurban variation in niching by Mexican, Salvadoran, Chinese, and Vietnamese men and women in four industries in Los Angeles. Niching is uneven; in some parts of the metropolitan area, these groups niche at high rates in these industries, whereas in others, there is no unusual concentration. We show how a group's propensity to niche in an industry is generally higher when the industry is located close to the group's residential neighborhoods and demonstrate the ways in which the proximity of competing groups dampens this geographic advantage. The study speaks to debates on immigrant niching and connects with research on minority access to employment and accounts of the agglomeration of firms. More generally, it links the geographies of home and work in a new way, relating patterns of immigrant residential segregation to those of immigrant employment niches. [ABSTRACT FROM AUTHOR]

Modernist planners became thieves of memory. Faustian in their eagerness to erase all traces of the past in the interest of forward momentum, of growth in the name of progress, their drive-by-windscreen surveys of neighbourhoods that they have already decided to condemn to the bulldozer, have been, in their own way, as deadly as the recent drive by gang shootings in Los Angeles. Modernist planners embracing the ideology of development as progress, have killed whole communities, by evicting them, demolishing their houses, and dispersing them to edge suburbs or leaving them homeless. They have killed whole communities by not understanding the loss and grieving that go along with losing one's home and neighbourhood and friends and memories. (Sandercock 1998:208) When watching the news, you find that the government is only concerned with shack dwellers. What about us? We are sitting with big expectations that they will build us houses. We have grown so old sitting in the backyards. Backyard shack-dweller, Johannesburg, 1999 [ABSTRACT FROM AUTHOR]

The article presents a study regarding information-economy growth and local economic development in Los Angeles, California metropolitan area. Local economic development policy is often characterized as an evolution from the first and second waves of incentive-based competition and cost-benefit-based assistance to the third wave strategy of demand-side activities. The local policy makers may be able to better construct economic development strategies from tax incentives to land subsidies and job training programs if cities are able to understand the location strategies of industries that are of growing economic importance.

The purpose of this research is to explore the changing geographical distribution of high-poverty neighbourhoods both between and within American metropolitan areas between 1990 and 2000. Of particular concern is the relative shift in the number of high-poverty neighbourhoods between central-city, inner-ring and outer-ring suburbs. A classification scheme is developed for identifying these three types of area. The results indicate that there has been an increase in the number of high-poverty neighbourhoods in the urban cores of economically stagnant old industrial cities of the Northeast and an increase in the number of high-poverty inner-ring neighbourhoods in Los Angeles, metropolitan areas in California's Central Valley and a few selected rapidly growing Sunbelt metropolitan areas. The analysis indicates that an increase in the number of urban core high-poverty neighbourhoods is linked to the general health of a metropolitan area's economy and that an increase in the number of inner-ring high-poverty neighbourhoods is linked to rapid population growth. [ABSTRACT FROM AUTHOR]

We examine the job transitions of Asian immigrants in the metropolitan economy of Los Angeles. In such ethnically heterogeneous cities, ethnic boundaries are porous and are mediated by an intermediate mixed economy. Ethnographic interviews reveal that many immigrants prefer jobs outside the ethnic economy to obtain higher wages and fairer work rules. Multivariate analyses find that, across a succession of jobs and over time, immigrants tend to drift away from the more informal ethnic economy of the metropolis, a move that leads to higher earnings. The use of ethnic ties to locate jobs also declines. The main attraction of participation in the ethnic economy is the opportunity for self-employment. Our model of the immigrant labor market moves beyond the dualist representation of the ethnic enclave economy. We conceive of the metropolitan labor market as shaped by firm size, degree of bureaucratization, and governance structure in which interethnic economic transactions are mediated through a growing mixed economy. [ABSTRACT FROM AUTHOR]

Introduces a series of articles featured in the `Journal of Urban History,' North American cities and suburbs. Changes in the social composition of cities and suburbs from the mid-nineteenth century to the mid-twentieth centuries; Danger posed by attempts to emphasize the diversity of suburbs; How metropolitan development in Los Angeles, California could have been shaped by public initiatives in transportation.

The problem of discovering regions that support particular functionalities in an urban setting has been approached in literature using two general methodologies: top-down, encoding expert knowledge on urban planning and design and discovering regions that conform to that knowledge; and bottom-up, using data to train machine learning models, which can discover similar regions. Both methodologies face limitations, with knowledge-based approaches being criticized for scalability and transferability issues and data-driven approaches for lacking interpretability and depending heavily on data quality. To mitigate these disadvantages, we propose a novel framework that fuses a knowledge-based approach using design patterns and a data-driven approach using latent Dirichlet allocation (LDA) topic modeling in three different ways: Functional regions discovered using either approach are evaluated against each other to identify cases of significant agreement or disagreement; knowledge from patterns is used to adjust topic probabilities in the learning model; and topic probabilities are used to adjust pattern-based results. The proposed methodologies are demonstrated through the use case of identifying shopping-related regions in the Los Angeles metropolitan area. Results show that the combination of pattern-based discovery and topic modeling extraction helps uncover discrepancies between the two approaches and smooth inaccuracies caused by the limitations of each approach. [ABSTRACT FROM AUTHOR]