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1.
In this paper, we develop a three-region economic geography model with workers of heterogeneous skills and mobility rates to consider how first-nature, regional differences impact both inter- and intraregional inequality. In our model, the skill premium within a region summarizes both the degree of intraregional inequality between mobile, skilled workers and immobile, unskilled workers and the interregional inequality through differences in the welfare of unskilled workers across regions. Regions with the highest skill premium have the greatest degree of intraregional inequality and provide the lowest level of welfare to unskilled workers, relative to other regions. We find that the skill premium will be higher in regions with a greater supply of unskilled labor, lower supply of housing, or are more remote. An increase in a region's housing supply or centrality will lower intraregional inequality and raise the welfare of the local, unskilled workforce. However, the magnitude of these changes are declining in the initial number of skilled workers in the region. The model is extended to consider imperfectly elastic housing supply. The larger the price elasticity of housing, the larger the range of values, such that more populated regions will host a disproportionate share of skilled workers, have lower levels of intraregional inequality, and provide higher levels of welfare for unskilled workers.  相似文献   
2.
Does the emergence of a new boundary‐spanning policy regime shift the focus of well‐established organized interests, or does it mobilize new ones? In this article, I show that interest groups with a presence in Washington before 9/11 rapidly—but temporarily—shift their attention to the homeland security issues. Established groups' entrenchment in antecedent subsystems appears to buffer against widespread policy disruption and interest upheaval. However, a new set of previously latent groups opportunistically mobilizes after the regime is institutionalized. Newly mobilized groups replace those that retreat back to the regime's antecedent subsystems. Though the policy regime fails to resolve the jurisdictional turf conflicts that triggered its creation, the institutionalization of homeland security generates its own original, distinct government demand for lobbying. Interests that previously had no business in Washington before 9/11 took advantage of the new opportunities the regime offered without supplanting interests established long before the Department of Homeland Security and its congressional committees existed.  相似文献   
3.
李伏明 《史学月刊》2006,(10):65-72
明清时期,松江府是全国的棉纺织业中心。从劳动生产率、劳动时间和劳动力数量等角度考察,明代晚期,松江府棉布产量最多为1575万匹,外销量最多为1305万匹;清代中叶产量最多为3000万匹,外销量在2600万匹左右。明代“松江棉布,衣被天下”,只是市场有效需求不足的结果。清代松江棉布销售区域大大压缩,并不是市场竞争的结果,而是基于其生产能力、运输成本以及与外地经济联系的结果。  相似文献   
4.
李爽  黄福才  饶勇  魏敏 《旅游科学》2006,20(5):1-7,25
本文对国外旅游界最具影响力的两大旅游研究刊物Annals of Tourism Research(ATR)(1974—2005)和Tourism Management(TM)(1980—2005)中运用计量经济分析方法的122篇文献进行了全面回顾。在对计量经济分析方法的构成情况及应用领域进行统计分析的基础上,对其在国外旅游研究中的应用演进情况做了归纳和概括。研究发现,计量经济分析方法正逐渐成为国外学者进行旅游研究的主要手段之一,其中回归模型、时间序列模型和面板数据模型是最常用的手段;方法的应用主要集中在旅游需求研究方面,其次是旅游产业与环境关系研究、旅游供给研究。从研究方法的应用演进来看,经过30多年的发展,从静态的零星运用到比较系统的、动态的多种方法的整合运用,计量经济分析方法在旅游研究中的应用日渐成熟。  相似文献   
5.
A team comprising a former Russian policymaker and American analysts of the current Russian energy policy examines the course of that policy and its limitations during the post-Soviet period. In the process, they critically analyze key problems in Russia's oil, gas, coal, and electricity sectors that represent a potential drag on growth of the entire Russian economy and at the very least call into question the sustainability of further increases in exports to the West. The authors explore in considerable depth and detail both the factors underlying the recent increase in government intervention in the energy sector and the likely consequences for domestic production, consumption, resource security, and critical exports. Journal of Economic Literature, Classification Numbers: L71, O13, Q40, Q48. 11 figures, 3 tables, 29 references.  相似文献   
6.
V. Vilarrasa 《Geofluids》2016,16(5):941-953
Fluid injection in deep geological formations usually induces microseismicity. In particular, industrial‐scale injection of CO2 may induce a large number of microseismic events. Since CO2 is likely to reach the storage formation at a lower temperature than that corresponding to the geothermal gradient, both overpressure and cooling decrease the effective stresses and may induce microseismicity. Here, we investigate the effect of the stress regime on the effective stress evolution and fracture stability when injecting cold CO2 through a horizontal well in a deep saline formation. Simulation results show that when only overpressure occurs, the vertical total stress remains practically constant, but the horizontal total stresses increase proportionally to overpressure. These hydro‐mechanical stress changes result in a slight improvement in fracture stability in normal faulting stress regimes because the decrease in deviatoric stress offsets the decrease in effective stresses produced by overpressure. However, fracture stability significantly decreases in reverse faulting stress regimes because the size of the Mohr circle increases in addition to being displaced towards failure conditions. Fracture stability also decreases in strike slip stress regimes because the Mohr circle maintains its size and is shifted towards the yield surface a magnitude equal to overpressure minus the increase in the horizontal total stresses. Additionally, cooling induces a thermal stress reduction in all directions, but larger in the out‐of‐plane direction. This stress anisotropy causes, apart from a displacement of the Mohr circle towards the yield surface, an increase in the size of the Mohr circle. These two effects decrease fracture stability, resulting in the strike slip being the least stable stress regime when cooling occurs, followed by the reverse faulting and the normal faulting stress regimes. Thus, characterizing the stress state is crucial to determine the maximum sustainable injection pressure and maximum temperature drop to safely inject CO2.  相似文献   
7.
We used hydrologic models to explore the potential linkages between oil‐field brine reinjection and increases in earthquake frequency (up to Md 3.26) in southeastern New Mexico and to assess different injection management scenarios aimed at reducing the risk of triggered seismicity. Our analysis focuses on saline water reinjection into the basal Ellenburger Group beneath the Dagger Draw Oil field, Permian Basin. Increased seismic frequency (>Md 2) began in 2001, 5 years after peak injection, at an average depth of 11 km within the basement 15 km to the west of the reinjection wells. We considered several scenarios including assigning an effective or bulk permeability value to the crystalline basement, including a conductive fault zone surrounded by tighter crystalline basement rocks, and allowing permeability to decay with depth. We initially adopted a 7 m (0.07 MPa) head increase as the threshold for triggered seismicity. Only two scenarios produced excess heads of 7m five years after peak injection. In the first, a hydraulic diffusivity of 0.1 m2 s?1 was assigned to the crystalline basement. In the second, a hydraulic diffusivity of 0.3 m2 s?1 was assigned to a conductive fault zone. If we had considered a wider range of threshold excess heads to be between 1 and 60 m, then the range of acceptable hydraulic diffusivities would have increased (between 0.1–0.01 m2 s?1 and 1–0.1 m2 s?1 for the bulk and fault zone scenarios, respectively). A permeability–depth decay model would have also satisfied the 5‐year time lag criterion. We also tested several injection management scenarios including redistributing injection volumes between various wells and lowering the total volume of injected fluids. Scenarios that reduced computed excess heads by over 50% within the crystalline basement resulted from reducing the total volume of reinjected fluids by a factor of 2 or more.  相似文献   
8.
进入"十二五"后,文物保护领域面临着新的发展形势。其中,科学和技术成果转化问题受到了高度关注,成为当前文化遗产保护领域的一大热点问题。目前,由于我国文化遗产保护科技成果转化的特殊性和相关领域科技事业发展的阶段性,文化遗产保护科技供给与需求脱节,科技成果转化率不高。针对这种状况,国家应建立激励评价体制,促进文博系统内外的合作,保证科技成果的有效供给和有效需求。  相似文献   
9.
城市居民休闲度假旅游需求实证研究——以南京为例   总被引:4,自引:0,他引:4  
黄燕玲  黄震方 《人文地理》2007,22(3):60-64,33
我国旅游业正在从观光游览型向休闲度假型转变。运用数理统计分析方法,以南京为例探析对城市居民休闲度假旅游需求进行研究。研究发现偏爱休闲度假的居民在旅游资源喜好、旅游活动偏好、购买行为、信息来源渠道、出游方式等方面与一般居民有着明显差异。据此探讨休闲度假产品的开发,分析未来的休闲度假旅游发展趋势,并提出相应的休闲度假旅游产品开发对策与建议。  相似文献   
10.
北京中低收入社区育儿人群的服务设施需求研究   总被引:1,自引:0,他引:1  
服务设施需求分析是建设社区生活圈和完整社区的基础。已有研究关注服务设施供给的空间配置或评价,对服务设施需求的研究并不多见,尤其缺少对育儿人群等细分人群的研究。本文以此为切入点,讨论在二孩政策和年轻人少子化观念影响下,社区应当给予育儿人群什么样的服务设施支持。基于2017年北京公平与包容调查问卷数据,本文采用有序多分类模型分析中低收入社区居民对教育、医疗等10类设施的需求偏好。结果显示育儿人群对各类设施的需求和访问频率都超出其他人群,且相关需求存在性别差异;二孩家庭对服务设施的依赖性强于独生子女家庭,且因子女处于不同年龄段的家庭需求也有所差异。最后,本文提出了育儿人群所需服务设施的分类体系,以期为精细化社区服务设施规划提供参考。  相似文献   
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