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.     

THE OTHER BURGESS MODEL

In addition to his famous concentric-zone model of urban form, Ernest W. Burgess in 1929 outlined an altitudinal-zone model. It proposed a positive relationship in “hills cities” between the socioeconomic status of residents and the elevations at which they live. This article suggests a theoretical rationale for this “other Burgess model” based on the role of amenities in contemporary residential choice. Its performance compares favorably to that of competing models in an empirical test in cities selected to approximate as closely as possible the conditions that it assumes. [Key words: amenities, E. W. Burgess, urban form.]     

Scenarios of global municipal water-use demand projections over the 21st century

Abstract

A comparison study is presented of three methods for evaluating trends in drought frequency: the standardized precipitation index (SPI), the Palmer drought severity index (PDSI), and a new method for estimation of dry spells (DS), which is based on average daily temperature and precipitation, and takes into account the length of a spell. The methods were applied to climate data from 450 stations in the Elbe River basin for the period 1951–2003, as well as data from several stations with longer observed time series. Statistical methods were used to calculate trend lines and evaluate the significance of detected trends. The dry spells estimated with the new method show significant trends in the whole lowland part of the Elbe basin during the last 53 years, and at the 10% level almost everywhere in the German part of the basin excluding mountains and the area around the river mouth. The SPI and PDSI methods also revealed significant trends, but for smaller areas in the lowland. The new DS method provides a useful supplement to other drought indices for the detection of trends in drought frequency. Furthermore, the DS method was able to detect statistically significant trends in areas where the other two methods failed to find significant trends, e.g. in the loess region in the southwest of the German part of the basin, where small insignificant changes in climate can lead to significant changes in water fluxes. This is important, because the loess region is the area within the basin having the highest crop yields. Therefore, additional research has to be done to investigate possible impacts of detected trends on water resources availability, and possible future trends in drought frequency under climate change.     

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。     

中美城市郊区化发展比较研究

20世纪美国城市经历了普遍的郊区化过程,深刻地重构了美国经济和社会结构。分析美国郊区化的发展历程、原因和影响;在探讨中国城市郊区化的特征和机制基础上,与美国郊区化进行比较。美国郊区化主要从20世纪20年代开始产生,经历了4个发展阶段,其动力机制主要是收入的提高、交通技术进步、小汽车的广泛使用、公共政策、电信技术的发展等,美国郊区化促进了美国都市区的发展,并造就了美国战后经济高速发展的同时,但也带来了一系列的社会问题,如空间不匹配、内城衰败等问题;中国城市郊区化开始发生于20世纪80年代,至今可以分为两个发展阶段,中国城市郊区化是在全球化、市场化、分权化的转型背景下发生和发展的,在具有郊区化一般规律的同时,与美国郊区化在发生背景、动力机制、影响等方面不同。未来中国城市郊区化将加速发展,应该吸取美国郊区化的经验教训,促进中国城市合理发展。     

Economic globalization and regional disparities in the Philippines

This paper empirically tracks the Philippine (policy) path following the mantra of economic globalization over the past 25 years. Specifically, it investigates the resulting regional growth‐inequality relationships and development footprints accompanying the restructuring of political economy and livelihoods. The Philippine case thereby shows how globalization can simultaneously cause the selective dismantling of (economic) barriers and enhancement of mobility and growth, as well as a deterioration of socioeconomic inequalities in space and society. In an increasingly deregulated and contested environment these development divides do not just pose serious threats to regional balance and national cohesion but, ultimately, undermine state capacity to achieve avowed goals of inclusive growth, stability and equality for citizens.     

清至民国洛川塬土地利用演变及其对土壤侵蚀的影响

依据史料和已有研究,恢复了洛川塬土地利用的演变过程及其对土壤侵蚀的影响。研究表明,清至民国时期是一个由土地垦殖的初步恢复到土地垦殖力度的增强、垦殖范围的扩大,再至战乱、自然灾害后期的重建以及民国时期土地垦殖发展的过程。地貌的复杂性、降水的不稳定性,对土地开垦造成客观限制;政策制度的推行对土地开垦起到主导作用;而人口因素是土地开垦的根本动力。土地开垦面积随不同时期的人口变化而呈现显著差异,即土地开垦面积和人口数量之间成正相关关系。洛川塬环境伴随着人口增长、土地利用强度增强而逐步恶化。这种恶化是地理环境系统自我调节能力减弱,继而引发土壤侵蚀加剧,并呈现为人为加速侵蚀和自然侵蚀交相混合的共同作用。     

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。     

气象信息安全建设探讨

为了解决北京气象信息网络安全和有效地满足气象信息共享、等级保护和未来发展的需求,在分析现有北京气象信息网络建设中存在安全风险的基础上,从人员思想意识、管理、技术等方面提出了一套比较完整的解决信息安全问题思路。结果表明：可从信息安全系统建设方面以安全等级划分作为首要切入点,建立安全域,解决办公网、业务网和互联网三网关联问题。将安全检查评估和加固贯穿到信息系统整个周期,采用网络安全联防机制安全准入方案解决VPN接入导致的网络边界模糊问题。可根据信息系统属性和损害客体及损害程度来划分信息系统等级。此研究思路,对气象信息系统安全的进一步发展有参考意义。