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1.
The standard theory of optimal jurisdictional size hinges on the existence of economies of scale in the provision of local public goods and services. However, despite its relevance for forced local amalgamation programs and related policies, the empirical evidence on the existence of such economies of scale remains elusive. The main goal of this paper is to produce an updated and comprehensive quantitative review of the existence of economies of scale in the provision of local public goods using a meta-analysis approach to systematize the wide range of empirical approaches and modeling frameworks found in the previous literature. Our analysis confirms the presence of moderately increasing to constant returns to scale in the provision of local services with no reduction in the average costs of production in the delivery of most local public services beyond a certain, modest jurisdictional size, which many studies have estimated at 10,000 residents. Also, the potential for economies of scale differs at least across three traditional services: education, water and sanitation, and garbage collection, being highest for education and lowest for garbage collection. Our analysis also offers guidelines for future empirical research in this area. Physical output and production cost data should be used, together with translog specifications for the modeling of cost functions. Last, we find evidence that the determinants of output cost elasticity include bidirectional publication bias and population density but do not include the presence or absence of modern “lean” production technologies or the (perceived) capital intensity of the sector, contrary to conventional wisdom. These findings have significant policy implications for countries considering jurisdictional consolidation programs.  相似文献   
2.
This paper examines settlement density and settlement patterns in the Roman colonial territories of Venusia, Cosa and Aesernia, located in three different landscapes of central southern Italy (modern Basilicata, Tuscany and Molise). Using a series of GIS tools, we conducted a comparative analysis of the density and spatial distribution of sites dating to the Hellenistic period (ca. 350–50 b.c.). We used the legacy settlement data collected by previous large-scale, intensive, site-oriented field surveys to test the validity of two competing rural settlement models of early Roman colonization: the conventional model of neatly organized settlements regularly dispersed across the landscape and the recently proposed theory that colonists adopted a polynuclear settlement strategy. After calculating the extent to which the archaeological datasets conform to the regular or polynuclear model, we conclude that only a very small portion of the colonized areas actually meets traditional expectations regarding the organization of early colonial settlements. Our analyses show that the legacy survey data is more consistent with the polynuclear settlement theory, but the data also reveals some completely unexpected patterns, suggesting that early Roman colonial landscapes were more diverse than previously thought.  相似文献   
3.
本文运用现代纺织科学的检测手段,分析了故宫博物院收藏的两件“羽毛纱”样品的组织结构和各项物理指标(织物单位面积质量、织物密度、纱线线密度、纱线捻度和捻度系数)及其织造方法,找到了同样织法的两块织物,存在不同面料风格的真正原因。古人通过巧妙的织造方法,充分发挥纺织原料各自的优点,织造出满足不同穿着目的的面料。  相似文献   
4.
This study compares the landscape-scale taphonomic signal of carnivore modification to the surficial bone assemblage in Amboseli Park, Kenya as it was in 1975 and 2002–2004. Change in predator abundances over time provides a means of assessing the taphonomic signal of carnivore-mediated bone consumption and destruction under differing ecological conditions and varying levels of conspecific competition for resources. The landscape assemblage indicates taxonomic variation in the patterning of carnivore modification to ungulates of different size classes as well as within equivalent size classes. Analyses of long bone elements indicate that the differential destruction of limb ends and the strength of the correlation between limb end abundance and bone mineral density provide an indication of the intensity of carnivore modification to a faunal assemblage. The ability to infer levels of carnivore modification based on limb elements can provide faunal analysts with the tools to determine whether the taphonomic signals in the fossil record relate to carnivore modification, hominin transport of appendicular elements, or both.  相似文献   
5.
J. J. Adams  S. Bachu 《Geofluids》2002,2(4):257-271
Physical properties of formation waters in sedimentary basins can vary by more than 25% for density and by one order of magnitude for viscosity. Density differences may enhance or retard flow driven by other mechanisms and can initiate buoyancy‐driven flow. For a given driving force, the flow rate and injectivity depend on viscosity and permeability. Thus, variations in the density and viscosity of formation waters may have or had a significant effect on the flow pattern in a sedimentary basin, with consequences for various basin processes. Therefore, it is critical to correctly estimate water properties at formation conditions for proper representation and interpretation of present flow systems, and for numerical simulations of basin evolution, hydrocarbon migration, ore genesis, and fate of injected fluids in sedimentary basins. Algorithms published over the years to calculate water density and viscosity as a function of temperature, pressure and salinity are based on empirical fitting of laboratory‐measured properties of predominantly NaCl solutions, but also field brines. A review and comparison of various algorithms are presented here, both in terms of applicability range and estimates of density and viscosity. The paucity of measured formation‐water properties at in situ conditions hinders a definitive conclusion regarding the validity of any of these algorithms. However, the comparison indicates the versatility of the various algorithms in various ranges of conditions found in sedimentary basins. The applicability of these algorithms to the density of formation waters in the Alberta Basin is also examined using a high‐quality database of 4854 water analyses. Consideration is also given to the percentage of cations that are heavier than Na in the waters.  相似文献   
6.
Today the area once known as the Grand Prairie in the American Midwest is best known for its high agricultural productivity and monoculture. Little of the original prairie landscape that gave the region its name remains. Prior to white settlement, the region was perceived as swampy, dangerous, unhealthy and unfit for agriculture. This ‘uninhabited waste’ and ‘giant emporium of malaria’ embodied the type of landscapes settlers initially tried to avoid. Ultimately, perceptions of the Grand Prairie landscape as well as the physical landscape itself were altered by settlement and improving drainage technology. This paper aims to link changes in the way the central Illinois landscape was imagined and perceived, with the subsequent environmental transformation that resulted in the near total elimination of tallgrass prairie and the wholesale alteration of regional hydrology through channelization and agricultural drainage.  相似文献   
7.
Accurate bone density data are essential for assessing the influence of destructive processes in archaeological faunal assemblages. Unfortunately, the diversity of methods employed by different researchers to derive density values has resulted in recent confusion. Two recent publications in this journal [J Archaeol Sci 29 (2002) 883; J Archaeol Sci 29 (2002) 979] exemplify this state of misunderstanding. Both studies argued that the role of bone density in shaping archaeological faunal assemblages has been largely overrated, but both based their conclusions on density values that were inaccurately derived. The former employed a method of calculating bone density that has been largely discredited over the past decade [J Archaeol Sci 29 (2002) 883]. Within a larger discussion of zooarchaeological methodology, the latter provided an assessment of the current state of bone density research that inappropriately characterized the discrepancies between available sets of density data as a reflection of the differences between two technologies—photon densitometry and computed tomography [J Archaeol Sci 29 (2002) 979]. The actual dichotomy exists—irrespective of the technology employed—between studies that account for variation in the shape of bone cross-sections and those that do not. The different sets of density data currently available to zooarchaeologists vary tremendously in their accuracy. We review and evaluate the different techniques employed in the research of bone density patterns of mammalian fauna. Computed tomography produces the most accurate density data. For elements without medullary cavities, photon densitometry may provide density values of similar accuracy but only if a method of cross-sectional shape-adjustment is applied.  相似文献   
8.
郝秉键  陈熙男 《史学月刊》2003,23(2):108-114
现代化之初,日本的人口有四个基本特征,即高密度、低增长率、低依赖性人口和高素质。高密度的人口是日本现代化的不利因素,如何化不利为有利是日本现代化的关键,而低增长率、低依赖性人口和高素质则是日本经济起飞的重要条件。  相似文献   
9.
以往学界对开埠初期上海租界水环境治理,一般采取填浜筑路的视角,而本文通过对档案资料的考察发现,租界当局对租界内的河浜采取了灵活的治理办法,对于挡路和阻碍市政的死水河浜进行填埋,而对于一般的潮汐河浜和航运河浜采取了清淤、疏通的保护措施,挖掘开通了新河浜,从而使河浜水系的功能得以延续。为了排水需要,租界当局辟建了下水道系统,其治理办法却借鉴于治河方法。  相似文献   
10.
南京市区就业空间布局研究   总被引:5,自引:0,他引:5  
王波  甄峰 《人文地理》2011,26(4):58-65
本文采取就业密度分析方法,对南京市区就业空间布局进行实证研究。在南京市区现有11个区的基础上将南京市区划分为159个研究单元。依据2005年南京市1%人口抽样调查资料中"区县层面"分行业就业数据,以及2006年南京市用地现状图,修正匹配得到各个研究单元制造业、服务业、商业金融业及总的就业密度值。并运用Arcgis软件对就业密度值进行核密度分析以及3D模拟,分析南京市区制造业、服务业以及总就业的空间布局特征及原因机制。  相似文献   
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