This paper presents an empirical investigation of the location strategy pursued by chain retailers over a period of 55 years. We use a unique data set containing the sequential location decisions of supermarkets and drug stores in a medium size U.S. city between 1956 and 2010. The data indicate that chain retailers located new stores within reasonable proximity to their already existing network of stores through most of the sample period. We propose a strategy to empirically identify whether spatial monopolization intent, economies of density, or both of these factors were the reason for such clustering behavior by chain retailers. Using a discrete choice model for location in geographic space, we find that economies of density were partially responsible for the clustering behavior in the supermarket industry, but not in the drug store industry. Moreover, spatial monopolization intent was a pursued strategy by both supermarkets and drug stores all along. We also find that in some cases up to 33.2 percent of consumers living between two stores owned by the same retailer found themselves trapped in space by the retailer, with no closer shopping alternative.

This dissertation investigates the economic consequences of urban sprawl for US minorities. Each essay focuses on a key empirical debate related to that relationship. The first essay establishes a set of attributes and empirical measures of sprawl based upon a comprehensive review of the literature. I define sprawl as a multi-faceted pattern of three land-use attributes: low density, deconcentration, and decentralization. I then resolve several methodological inconsistencies in the measurement of sprawl. Extensive analysis of spatial and economic data finds that metropolitan areas do not commonly exhibit high- sprawl (or low-sprawl) features across multiple measures. Instead, they often exhibit unique combinations of low-sprawl and high-sprawl attributes. The second essay examines the effect of sprawl on minority housing consumption gaps since the housing bust. I make two contributions to the literature. First, I reveal a facet of the relationship between sprawl and the Black-White housing gap not examined by previous econometric studies: Sprawl only contributes to reducing that gap once a metropolitan area reaches a critical threshold level of sprawl, typically at high levels of sprawl. Below a threshold, sprawl facilitates an expansion of the Black-White housing gap. Second, I compare results for Blacks, Asians, and Hispanics using recent data. For Blacks, the benefits from sprawl occur above an even higher threshold, as compared to preceding studies using 1990’s data. For Asians, sprawl yields significant gains in housing consumption relative to Whites. As such, arguments that anti-sprawl policies reduce minority gains in housing should be treated with considerable skepticism in the post-Great Recession economy. The third essay explores the relationship between sprawl and racial and ethnic segregation. This econometric study advances the understanding of that relationship in two ways. First, I examine the effect of countervailing patterns of multiple land-use attributes, i.e. unique combinations of low-sprawl and high-sprawl attributes, on all five of the dimensions of segregation. Second, I compare outcomes for Blacks, Hispanics, and Asians. The study analyzes the contribution and transmission of countervailing spatial patterns of land use to increasing (or decreasing) segregation. These complex effects bring new precision and insights to the analysis of racial and ethnic inequality in an age of rapid demographic change.

Political districting is an intractable problem with significant ramifications for political representation. Districts often are required to satisfy some legal constraints, but these typically are not very restrictive, allowing decision makers to influence the composition of these districts without violating relevant laws. For example, while districts must often comprise a single contiguous area, a vast collection of acceptable solutions (i.e., sets of districts) remains. Choosing the best set of districts from this collection can be treated as a (planar) graph partitioning problem. When districts must be contiguous, successfully solving this problem requires an efficient computational method for evaluating contiguity constraints; common methods for assessing contiguity can require significant computation as the problem size grows. This paper introduces the geo-graph, a new graph model that ameliorates the computational burdens associated with enforcing contiguity constraints in planar graph partitioning when each vertex corresponds to a particular region of the plane. Through planar graph duality, the geo-graph provides a scale-invariant method for enforcing contiguity constraints in local search. Furthermore, geo-graphs allow district holes (which typically are considered undesirable) to be rigorously and efficiently integrated into the partitioning process.

Este paper tiene cómo objetivo principal entender cómo la inmigración afectó a los niveles de educación secundaria de Estados Unidos durante la primera parte del siglo XX. La investigación se centra en dos potenciales canales de impacto: El ?crowding out? del sistema público generado por la llegada de inmigrantes en edad escolar y un impacto sobre el retorno a la educación generado por la in- migración adulta de baja cali?cación. Utilizando variables instrumentales para la inmigración, se encuentra que la inmigración de adultos afecta positivamente la matrícula y graduación (medidas como tasa total) y que la inmigración de niños las afecta negativamente. Finalmente, se encuentra evidencia de que la inmigración pudo haber producido una salida de una masa de estudiantes desde la educación pública hacia la educación privada.

Objectives: This study described the prevalence of and risk factors for sensory deficits, cognitive and physical functional limitations, and disability among older Southeast Asian refugees in the United States. Methods: Data for the regression analyses were drawn from the 2003-2007 American Community Surveys. The sample included foreign-born persons aged 55 and older who were classified as Hmong, Cambodian, Laotian, and Vietnamese. Results: Hmong, Cambodian, and Laotian persons were more likely to report a sensory deficit, functional limitation and disability than Vietnamese persons. Year of arrival, English language proficiency and education were important risk factors. Hmong and Cambodian groups had the most negative health profiles. Discussion: Previous studies found that Vietnamese were the most health disadvantaged when compared to other Asian American groups and Whites. When compared to other refugee populations, the Vietnamese were actually the advantaged group. Our results indicated additional research on the disablement process among Southeast Asians is warranted.

We examine urbanization using new data that allow us to track the evolution of population in rural and urban areas in the United States from 1880-2000. We find a positivecorrelation between initial population density and subsequent population growth for intermediate densities, which increases the dispersion of the population density distribution over time. We use theory and empirical evidence to show this pattern of population growth is the result of differences in agriculture's initial share of employment across population densities, combined with structural transformation that shifts employment away from agriculture.

During the Great Recession, the rate at which Americans formed households fell sharply. Though the rate has recently picked up, it isnt fast enough to make up for the shortfall in household formation that occurred over the last several years. An analysis of recent household formation patterns shows that the greatest shortfall occurred among young adults and that it is related to weak economic conditions. Housing choices have shifted as well, with a greater proportion of young households living in rental housing rather than owner-occupied homes.

The subprime lending catastrophe and the Great Recession that it triggered have cast a pall over the postindustrial city of Flint, Michigan, and its increasingly bleak suburbs. Arriving after many years of General Motors (GM) factory shutdowns, gnawing population losses, and an earlier episode of predatory lending that very few people even remember today, the most recent rash of home foreclosures has shaken this already ailing metropolis in a relentless, decade-long aftershock. According to most local observers, the Vehicle Citys latest meltdown commenced shortly after the dawn of the new millennium, when thousands of area homeownersmany of them financially overstretched by a combination of unemployment and high-interest subprime loansbegan defaulting on their mortgages and property taxes. Between 2002 and 2009, officials from the Genesee County Land Bank, a public receiver for abandoned and tax-foreclosed properties, quietly repossessed nine thousand homes, businesses, and lots just within Flint, a figure that accounted for 14 percent of the citys overall surface area. Meanwhile, in the private lending market, mortgage foreclosures were surging to Depression-era levels, routinely exceeding a thousand homes per month. Just during September 2010, [End Page 572] for instance, nearly 1 percent of the regions two hundred thousand housing units slipped into foreclosure. By decades end, the toxic trio of deindustrialization, tax delinquency, and predatory lending had pummeled the local housing market into a state of near collapse, with average sale prices for homes in Flint reduced to just $17,000significantly cheaper than the Buick sedans that GM workers once assembled on the citys North End...

Since the 1970's, Fernand Braudel has urged for the integration of space in historical analysis, pointing towards to what we call nowadays a "Geographically-Integrated History". For this historian, the creation of a map as an analytical support was necessary to comprehend men's evolution, in the belief that change happens in a space-temporal frame. Our work is being developed within the research project DynCoopNet ("Dynamic Complexity of Cooperation-Based Self-Organizing Commercial Networks in the First Global Age") which goal is to reveal the mechanisms of cooperation among merchants that tied together the self-organizing commercial networks of the First Global Age (1400-1800). Focusing on the notion of dynamic that implies an integration of space and time, our aim is to develop a spatial analysis, highlighting the role of space on network building. This paper intends to present an innovative approach that demonstrates the benefits of carrying on spatio-temporal analysis of historical data sources.

Este paper tiene como objetivo principal entender como la inmigración afectó a los niveles de educación secundaria de Estados Unidos durante la primera parte del siglo XX. La investigación se centra en dos potenciales canales de impacto: el crowding out del sistema público generado por la llegada de inmigrantes en edad escolar y un impacto sobre el retorno a la educación generado por la inmigración adulta de baja calificación. Utilizando variables instrumentales para la inmigración, se encuentra que la inmigración de adultos afecta positivamente la matrícula y graduación (medidas como tasa total) y que la inmigración de niños las afecta negativamente. Finalmente, se encuentra evidencia de que la inmigración pudo haber producido una salida de una masa de estudiantes desde la educación pública hacia la educación privada.

This paper uses new data on state-level physical capital by sector and land in the farm sector for the states of the United States from 1840 to 2000. These data are incorporated into aggregate development accounting exercises, with the aim of comparing cross-state results to those found in cross-country samples. Preliminary findings are that input variation explains more than half of the observed variation in output per worker, and generally more than 40% of the variation in sectoral output per worker across states. There is evidence for intergenerational human capital accumulation, as input variation explains more than two-thirds of the observed variation in output per worker, and generally more than half of the variation in sectoral output per worker across states. These ndings are generally robust to across regions of the US.

The Interstate Highway System is a product of the 1930s and 1940s, yet remains essential to U.S. transportation in 2012 and for the foreseeable future. This analysis examines how the Interstate Highway System has changed since its inception in 1938, first map in 1947, and the beginning of construction in 1956. The mileage has grown considerably, allowing for many new routes, and the spatial coverage of the network has been extended to allow many new metropolitan areas to be connected. This has lowered connectivity but increased the metropolitan population served. A GIS dataset was created for the 1947 network, allowing it to be compared to the current network using standard accessibility measurement techniques. This research shows that the Interstate System has not kept up with population shifts in the South and West, and there is no correlation between accessibility change and population change. The greatest improvements have in fact taken place in the densest part of the network, not where population or traffic growth has been greatest. It has therefore reinforced advantages held by places already well placed on the original 1947 network. The old American Manufacturing Belt continues to provide an effective regionalization for capturing variations in the Interstate network, though it has become the Rustbelt and is of declining importance within the country.

The existing solutions to privacy preserving publication can be classified into the homogenous and non-homogenous generalization. The generalization of data increases the uncertainty of attribute values, and leads to the loss of information to some extent. The non-homogenous algorithm which is based on ring generalization, can reduce the information loss, and in the meanwhile, offering strong privacy preservation. This paper studies the cardinality of the assignments based on the ring generalization, and proved that its cardinality is α n (α > 1). In addition, we propose a semi-homogenous algorithm which can meet the requirement of preserving anonymity of sensitive attributes in data sharing, and reduce greatly the amount of information loss resulting from data generalization for implementing data anonymization.

WorldMap is a web-based, map-centric data exploration system built on open-source geospatial technology at Harvard University. It is designed to serve collaborative research and teaching, but is also accessible to the general public. This article explains WorldMap's basic functions through several historical research projects, demonstrating its flexible scale (from neighborhood to continent) and diverse research themes (social, political, economic, cultural, infrastructural, etc.). Also shared in this article are our experiences in handling technical and institutional challenges during system development, such as synchronization of software components being developed by multiple organizations; juggling competing priorities for serving individual requests and developing a system that will enable users to support themselves; balancing promotion of the system usage with constraints on infrastructure investment; harnessing volunteered geographic information while managing data quality; as well as protecting copyrights, preserving permanent links and citations, and providing long-term archiving.

This report details how much families throughout the state of Iowa must earn in order to meet their basic needs and underscores the importance of public work support programs for many Iowans who, despite their work efforts, are not able to pay for the most basic living expenses. The report also details how many working Iowa families are falling below the minimum cost-of-living threshold. The basic-needs budgets constructed for this report represent a very frugal living standard and include allowances for rent, utilities, food prepared at home, child care, health care,transportation, clothing and other household necessities. The budgets show the after-tax income an Iowa family would require to meet basic needs without the benefit of public assistance or work supports.