Contingent Urban Geographies of Violent Crime: Racial Segregation and the Impact of Public Housing in Atlanta

Neighborhood variations in crime incidence rates are most commonly interpreted through the lens of social disorganization theory, or a "communities and crime" perspective. This approach typically articulates explanation for crime by focusing on the characteristics of communities—a unitary scale most commonly equated with neighborhoods. We argue that this perspective fails to recognize the importance of broader urban geographic contexts, and offer an extension that sees geographically contingent processes functioning at multiple scales simultaneously. We develop this perspective applied to the "spread effects" of public housing on violent crime in surrounding neighborhoods: these spread effects are conditioned by the nature of the urban contexts through which they operate. Specifically, deeply divided and racialized patterns of residential segregation at least partially define the contexts that condition public housing's effect on crime. We examine our perspective using early 1990s block group data for the City of Atlanta and find substantial evidence in support of our perspective. In particular, we find that Techwood Homes, the nation's first federally constructed public housing project, exerted different geographic spread effects in predominantly White than in predominantly Black portions of the city. By failing to recognize the complexity and contingency of public housing's geographic effect on crime in surrounding neighborhoods, previous approaches substantially overestimate crime in White areas, and underestimate crime in Black areas.     

Long-Term Appreciation of Owner-Occupied Single-Family House Prices in Milwaukee Neighborhoods

Annual price indices of owner-occupied single-family houses are estimated for 111 neighborhoods in Milwaukee, Wisconsin, for the period of 1971-1993 using hedonic price methods controlling for quality differences across housing units. The rates of price appreciation vary significantly from neighborhood to neighborhood. During the 22-year study period, nominal house prices in some neighborhoods increased more than 500%, whereas those in others decreased. In general, the neighborhoods close to each other exhibit similar price movements. In some cases, however, there are sharp differences between the neighborhoods when strong boundaries, such as a river or an expressway, exist between them even though the physical distance between them is small. Poor neighborhoods generally have experienced low appreciation rates, although the racial composition and the crime rate in the neighborhood seem to contribute the differential as well.     

Buying Development: Housing and Urban Growth in Guadalajara,Mexico

This study analyzes how Mexican federal housing policy affects the production of space and the housing landscape in Guadalajara, Mexico. Using a wide-ranging database of parcels developed in metropolitan Guadalajara, we map all housing developments from 1970 to 2000 and classify them into three categories that reflect different development processes. The greatly increased number of social-interest houses, and the large extension of land area developed since 1990 are explained by federal housing program reforms. Informal settlements remain a major path to home ownership, but the percentage of housing developments that are informal and the percentage of informally developed land have declined since the 1980s. We also discovered a trend of increasing land area devoted to low-density, élite enclaves, and analyzed marketing strategies and land use patterns that occurred in these newer developments. All of these outcomes reflect a neoliberal ideology that promotes consumption and the privatization of space, but largely excludes the urban poor. The result is higher rates of home ownership, but in an increasingly segregated and fragmented landscape poorly served by public infrastructure and lacking in amenities.     

内城区户籍贫困空间剥夺式重构研究——基于南京10843份拆迁安置数据

采用南京内城区2001-2011 年期间10843 户贫困家庭的拆迁安置数据,探讨内城区户籍贫困空间格局及其重构特征。通过空间自相关与空间聚类等研究方法,对城市拆迁发生前内城区22 个街道的贫困家庭分布格局分析发现:① 样本贫困群体在街道尺度上社会经济属性相对均质,主要贫困属性因子的空间自相关性不强;② 内城区户籍贫困空间格局具有良好的历史延续性,总体上呈分散布局并遵循着自然渐进式的空间演化模式;③ 拆迁安置导致内城区贫困空间发生由中心至边缘、由分散到集中的重构,而且这种贫困空间边缘化过程具有强烈的不可逆性;④ 贫困家庭的物质居住条件通过拆迁安置得以改善,代价是因搬离内城而远离商业区、重点中小学、三甲医院和地铁站点等城市优质公共资源。内城区贫困空间剥夺式重构过程中,城市优势区位的丧失有可能导致贫困家庭的交通、就业与生活成本增加,向上流动机会减少。     

转型期广州市生命历程与住房产权转换

作为家庭生命历程中的重要事件,住房产权转换与家庭特征变化、个人与工作单位的关系以及区域住房市场环境变化紧密相关。采取事件史分析方法,将住房产权转换与个体生命历程中的重要事件关联起来,分析住房产权转换的影响因素。对住房产权转换的持续期的研究发现,处于租房状态下的住户改变产权状态的愿望较强,但产权一旦进入自有状态,居民改变产权的愿望就会降低;从住房产权的生存时间来看,最终向全部产权转变的生存时间最长,其次是向资助产权的转变,最短的是向租房产权转变;通过建立COX’s比例风险模型分析发现,家庭生命周期变化和组织变量对住房产权转换的影响都非常显著,说明在中国特殊背景下,住房产权的转换不仅与家庭基本特征变化密切有关,还与个人单位的基本特征密切相关,这正是转型时期计划体制和市场分配体制双重力量相互作用的结果。     

Acceptance limits for performance‐based seismic design of RC walls for low‐rise housing

Acceptance limits of the structural response of walls for low‐rise concrete housing were developed. Proposed values are applicable within a performance‐based seismic design framework. Acceptance limits are based on performance indicators of structural response–allowable story drift ratios, width of residual cracks and residual damage index, and expected damage of walls. Cracking limits were defined from parameters obtained at the unloading stage of walls (i.e., residual cracking stage). The residual cracking stage may be used for structural damage evaluation and cost estimation of structural rehabilitation after an earthquake has occurred. The performance indicators proposed herein were derived from test observations and measured response of 39 RC walls' specimens during shaking table and quasistatic testing, as well as from limiting values and results of previous studies. Copyright © 2012 John Wiley & Sons, Ltd.     

2007年宁洱6.4级地震灾害中的农村民房恢复重建模式研究——以宁洱镇民政村为例

基于2007年6月3日云南省宁洱6.4级地震灾区的实地考察和走访,结合对相关文献和救灾档案资料的综合分析,以宁洱镇民政行政村为典型实例,系统地阐述了该次地震灾害中农村民房恢复重建的模式,初步分析了这种恢复重建模式的关键环节、优势和面临的困难,并提出了一些改进该模式的建议,以期为今后的地震恢复重建工作提供一些借鉴。     

土地出让价格信号引起的房价变化时空扩散效应

从信号传递角度出发,研究土地出让事件冲击带来的房价变化在时间和空间上的扩散效应。利用杭州2006年1月-2010年3月177宗住宅用地成交数据和251个新建商品住宅楼盘交易数据,借助GIS相关软件展开实证研究,结果发现:①土地出让价格信号引起房价的变化,对房价的影响具有“不对称性”;②房价变化以出让地块为中心往外扩散,呈现“波纹效应”;③房价变化具有“持续性”,土地出让价格信号对房价的影响持续四个月,影响范围达3 km以上;④房价波动强度随时间推移和空间延伸不断渐弱。对此,政府应尽量保持地价平稳,规避地价信号所产生的市场波动风险。     

广州住房与保障房的建设与评价

以广州12个保障房社区的问卷抽样调查为基础,从住房建设与住房结构、保障房建设、保障性住房社区3个层面探究了城市住房与保障房的关系,对当前广州保障房社区现状进行定量分析,并从社区层面检验当前保障房建设模式下的实际效果。研究发现,总体上,20世纪90年代后广州住房质量提升明显,配套设施不断完善,但住房拥有率低,租赁住房是城市居民的重要选择;且住房市场的发展并未较好地解决居民的住房需求,保障性住房缺口较大,城市住房保障职能部分转嫁于城中村等“非正规”居住空间,住房保障体系仍有较大的提升空间。在保障房社区层面,存在部分配套设施可达性低、居民社区参与程度低等问题,但居民的满意度较高,居住意愿达到了89.2%,这表明当前大规模保障房建设具有其合理性。但当前保障房建设模式忽视了保障房社区的后续发展,已出现社区居民社会融合度低、发展机会少等问题,并可能向新的贫困集聚区演化。     

基于核密度估计的南京二手房活跃度特征及影响机制研究

随着越来越多住房可通过网络查询和交易,为住房空间研究提供一个全新数据来源。本文通过对南京搜房网二手房数据挖掘,采用核密度估计空间分析方法,研究南京二手房活跃度的空间特征,重点探讨不同二手房活跃度影响因素,并通过河西、大光路和夫子庙3个案例,实证二手房活跃度的影响机制。研究发现,南京二手房活跃度空间呈现“一心三组团”的结构。二手房活跃度高的地区主要集中在南京市鼓楼区和建邺区;东部玄武高教区、南部江宁二手房活跃度较低,住房空间较为固化,居住空间发展较为成熟。影响二手房活跃度空间差异主要有住房内因和住房外因2个方面。通过多元回归模型分析表明,住房内因的价格、住房层数、绿化率和装修程度和外因的学区、地铁和区域变量显著影响二手房活跃度。居住层数、物业管理费、生活配套设施在活跃度高低2个层面 显著。