Trade and migration in a two-city model of transportation investments

A two-city model is developed in which both migration and trade of goods between two cities take place and the spatial structure of each city is recognized explicitly. Within this framework, reductions in intra- and inter-city transportation costs are evaluated from the viewpoint of the residents' welfare in each city. Of particular interest are the conditions under which the consumers' surplus measure is exactly equal to the area to the left of the relevant transportation demand curve.     

Tariffs, factor prices, and welfare in a spatial oligopoly

In this paper we derive endogenous tariff rates for a tariff revenue maximizing policy and a welfare maximizing policy (optimal tariff) in a spatial framework. The underlying model is that of a spatial oligopolistic market with domestic and foreign firms. We assess the outcomes of the model for different tariff rates and the free trade situation, the stress being on welfare considerations. Compared to the traditional theory of international trade and tariffs, this approach affords useful insights into the role of firms‘ locations and transportation costs for profits and consumers‘ surplus in the case of alternative trade policies. Received: February 1996 / Accepted in revised form: April 1997     

Design and optimization of small hydropower systems in water distribution networks under consideration of rehabilitation measures

Small hydro power systems (SHPSs) are increasingly installed in water distribution systems (WDSs). With only minor adaptations in a WDS, pressure surplus can be utilised. In such systems, a water surplus is also often available. In this work, water consumption data of a real Alpine WDS over one year are used as an input for an Epanet2 long-term simulation model to assess such a SHPS. In addition, the combinations of pressure and water surplus devices in a WDS are investigated. For such a specific investigated case, the yearly profit of 1750 € for a single SHPS could be increased to 3550 € when combining two interacting devices. Further, necessary and upcoming rehabilitation measures are investigated concerning their positive impact on the energy production potential and how additional costs (e.g., higher diameters (200 mm instead of 125 mm)) can be compensated by additional profits from energy production (maximum 5250 € per year).     

Examining the role of amenities in migration decisions: A structural estimation approach

I develop a discrete choice dynamic migration model to examine the importance of amenity values in immigrants' migration decisions. The model accounts for differentials in both wages and location‐specific amenities as determinants of migration decisions, and the size of migrants' networks is allowed to influence the value of the US location choice as well. By estimating the model using panel data from the Mexican Migration Project, I find that Mexican migrants place substantial value on amenities in the United States, which are shown to fall precipitously with migrants' age. Simulation results from policy experiments indicate that Mexican immigrants are more responsive to a policy that reduces the amenity values related to unauthorized US residence than to an increase in the number of border patrol officers.     

An intra-industry trade model in a vertical differentiation framework

We developed a partial equilibrium model in which intra-industry trade arises as a result of utility maximization of consumers and profit maximization of firms. The driving force for intra-industry trade is non-homothetic preferences of consumers. We utilized a vertical differentiation framework, in which consumers have the same tastes for quality but different income levels determining their non-homogeneous choices. All firms in all countries have access to the same production technology, and there are no differences in factor endowments. Intra-industry trade arises as a result of each firm specializing on a certain segment of the market in all countries. We solved the model numerically for a two-country two-firm setup. In this setup, firms choose their product quality level and their price by maximizing their profits in a two-stage optimization problem. They also decide whether to export to the foreign market or to concentrate only on the domestic market in a standard two-by-two game. With introduction of non-zero transportation costs, trade volumes in both directions decrease. Transportation costs are shared between consumers and firms according to the marginal demand in the domestic versus in the foreign country. This model supports Krugman’s home market effect: In case of non-zero transportation costs, firms want to locate their production site in the country where there is higher marginal demand for their product.     

SPECIAL DISTRICTS: A COMMON SOLUTION TO POLITICAL PRESSURES STEMMING FROM CITy-COUNTy FISCAL INEQUALITIES

Fiscal inequalities between cities and counties have long strained intergovernmental relations between these general purpose local governments. Historically they have tended to be competitive in their search for revenues but this competitiveness changed to greater cooperation as a consequence of the taxpayer revolts of the 1970s. Both cities and counties favored creation of special districts (with taxing power) to relieve some of the pressure on their own property tax structures. Traditional theories of government fragmentation have maintained that creation of special district governments further widens city-county fiscal inequalities; however, newer theories suggest the opposite. Through an analysis of increases in special districts and changes in city-county property tax level differentials, this study shows that creation of special taxing districts in the 1970s reduced property tax level differentials between cities and counties—an important economic and political effect in an age of taxpayer revolts aimed at city, county, and state property taxes but never at special district taxes.     

差速器对装载机工作性能的影响及差力差速器的研制

分析差速器对装载机工作性能的影响，简要介绍各种差速器的特点，并推出一种性能优良的差力 速器。该差力差速器的优点是：能充分发挥装载机的装载能力，改善了牵引性能和通过性能；可防止车轮滑及功能损失；差速性能好，转向阻力小；能高效，自动，连续平稳差力差速；制造简单。     

Time‐Dependent Discrete Network Design Frameworks Considering Land Use

Abstract: This article proposes optimization frameworks for discrete road network design considering the land‐use transport interaction over time. Unlike existing models, the optimization frameworks can determine the optimal designs automatically without trial‐and‐error once the objective(s) is/are clearly defined. Moreover, these frameworks allow the evaluation of the impacts of the optimal designs on the related parties including landowners, toll road operators, transit operators, and road users, and help network planners and profit‐makers with decision making by eliminating many alternative designs. A numerical study is set up to examine road network design's effects on these related parties under three road construction schemes: exact cost recovery, build‐operate‐transfer, and cross‐subsidization. The results show that the changes in landowner profits are not the same after implementing any scheme. These unequal changes raise the issue of the landowner equity. This implies that the government has to consider trade‐offs between parties’ objectives carefully.     

Does wage differential driven migration continue to exist? Tests on the role of regional economic structure in wage differential driven migration

This paper explores the role of regional economic structure in the wage differential driven migration among the US Metropolitan Statistical Areas for three discrete time periods from 1993 to 2004. Rapidly increasing interregional trade attributes to the restructuring process of production internationally and interregionally. Both trade and migration can contribute to the equilibrium conditions in regional labor markets. When fragmentation increases intra-industry trade (IIT) in interregional trade, do we expect to see the increasing roles of interregional trade toward the equilibrium condition in regional labor markets? Fragmentation may force some production stages to the other regions, in other words, firms may benefit from relocating to the regions where they can minimize labor costs with cheaper wage rates. In this restructuring process, similarities in regional economic structures may increase the volumes of IIT and as a result, we may expect to see the increasing complementary role of trade in factor price equalization to migration. In contrast, when regional economic structures are quite different, migration rather than trade plays more important role in factor price equalization. Consequently, the main flows of interregional migration caused by wage differentials are more likely to be found among the regions where regional economic structures are dissimilar.     

Efficiency and equity considerations in financing agricultural research and extension

Benefits resulting from agricultural research and extension activities conducted in one region may affect producers and consumers throughout the country. Measurement of these benefit spillovers is required to equitably and efficiently finance these activities. Spillover benefit ratios per dollar of internal benefits for all farm production regions in the United States are calculated using an economic surplus framework to account for the effects of research and extension on both producers and consumers. In nine out of ten regions, the spillover ratios are greater than one, indicating that benefits accruing outside the region conducting research and extension activities are greater than the benefits accruing internally to the region. The average spillover ratio, which is 3.71 for all regions, is greater than the ratio of federal expenditures to regional expenditures. The implication of these ratios being unequal is that the federal contribution would need to be increased in order for regional costs to match regional benefits.     

基于生产性服务业的中国城市网络研究

借鉴世界城市网络(WCN)的概念框架,从三个层面分析了中国大陆地区生产性服务业的城市网络体系。基于中国城市网络(CCN)的计算结果,研究认为:生产性服务业企业的区位竞争不再仅依赖于线性地拓展腹地赢取空间垄断地位,而是以网络化的布局模式在核心城市设立分支机构以实现利润的最大化;在城市节点层面,上海、北京成为主要的生产性服务业集聚城市,沿海的城市群则成为生产性服务业的主要集聚区域,内地的大部分城市处于生产性服务业链接程度相对较低的外围;在城市网络层面,城市之间关联网络中的首位效应(北京—上海的关联)非常明显,三大城市群中核心城市(北京、上海、广州、深圳)之间的网络构成了中国大陆地区生产性服务业的核心链接。     

Nonlabor income measures of capital intensity versus capital stock measures in estimatingthe determinants of regional labor productivity differentials: The manufacturing sector

This study is concerned with the estimation and explanation of regional differentials in productivity and with nonlabor income per unit of labor is a usable capital intensity proxy in the estimation of Cobb-Douglas production functions. The approach is to estimate labor productivity as a function: first of regional dummy variables and urbanization; second, of these variables plus capital intensity and other production function variables; and third, of all these variables plus labor force characteristics. Large regional labor productivity differentials emerge. Adding capital intensity measured either as capital stock or nonlabor income per unit of labor substantially reduces these differentials. Adding labor force characteristics then completely eliminates the differentials in most instances. At this point, however, it becomes clear that the estimates based on nonlabor income per unit of labor are as good as, if not better than, those based on the capital stock measure. Finally, the productivity disadvantage of the South is related to its low levels of education and unionization.     

考量生态系统服务供需关系的流域城市 生态空间优化研究——以青弋江流域泾县段 为例

快速城市化阶段,流域城市对生态系统服务的需求 与日俱增,生态系统服务供需失衡加剧,厘清及优化流域城市 生态系统服务的供需关系对于流域生态保护与经济发展的协同 具有重要意义。以长江下游最大支流——青弋江所贯穿的安徽 省泾县为例,运用生态系统服务空间定量评估方法,测算固碳 释氧、水文调蓄、土壤保持、生境支持、粮食生产、休闲游憩 6种关键生态系统服务的供需水平;通过四象限法,判定供需 关系并辨明平衡、赤字、盈余3类区域;以供需平衡为目标, 基于“保护平衡区与赤字区,开发盈余区”的策略设定用地情 景,利用CA-Markov模型获取供需约束的生态空间布局。结 果表明：1)生态系统服务供给的分布以高质量生态要素为基 底,呈南高北低态势,需求分布与人类活动集中区较吻合,在 县域中部和南部突出;2)研究区供需关系整体匹配,平衡区占 比最大,盈余区其次,赤字区最小;3)供需约束情景在非生 态空间向生态空间转入上表现较好,能增加林地、水域、草地 3类重要生态资源的存量,且在形态上可维护大型生态斑块的 完整性并引导城镇空间走向紧凑;4)依据供需关系设定的生态 保护空间与生态保护红线在平衡区较一致,但在盈余区与赤字 区,后者出现“开天窗”式的管控缺口,使青弋江破碎,而前 者未有该现象。     

The earnings of self-employed Mexican Americans along the U.S.-Mexico border

We utilize data from the 1990 1% Public Use Microdata Sample to analyze the earnings and occupational status of self-employed Mexican Americans in the five major U.S.-Mexico border metropolitan statistical areas (Brownsville, El Paso, Laredo, and McAllen in Texas, and San Diego, California) relative to those in non-border cities. Our findings suggest that self-employed Mexican American men earned significantly less in Texas-Mexico border cities than in other areas on average, while the earnings of self-employed Mexican American women did not significantly vary between border and non-border cities. We also find evidence that these earnings differentials may be related to differences in self-employment selection and occupational choice. As such, “across the board” policies designed to foster self-employment may not have the desired effect of boosting economic prosperity unless consideration is given to the socioeconomic and demographic composition of the region as well as to the specific occupational sector. Received: June 2000/Accepted: December 2000     

Bayesian posterior prediction and meta-analysis: an application to the value of travel time savings

In the evaluation of transportation infrastructure projects, some non-tradable goods such as time are usually key determinants of the result. However, obtaining monetary values for these goods is not always easy. For this purpose, this paper presents an approach that combines Bayesian posterior prediction and meta-analysis. This methodology will allow obtaining predictive distributions of the monetary values for this type of goods. Therefore, uncertainty is formally considered in the analysis. Moreover, the proposed method is easy to apply and inexpensive both in terms of time and money. Finally, an illustrative application to the value of travel time savings is also presented.     

Production,reproduction, and underdevelopment: petty commodity producers in Ujung Pandang,Indonesia

This discussion is based on a case study of the Indonesian city of Ujung Pandang. A group of petty commodity producers is examined. It is argued that in order to understand the reasons for the stagnation of petty production in Ujung Pandang, it is necessary to appreciate the internal stucture of petty production and the relationship between petty production and the capitalist and peasant sectors of the economy. The transfer of economic surplus out of petty commodity production which characterizes these relations is important to an understanding of the poverty of the petty producers in the city, whereas the class formation this promotes perpetuates the underdeveloped character of the economy. The same processes also mean that petty commodity production has an important role in the reproduction of the dominant capitalist sector of production because of the support it unwittingly gives to the wage labor force. These processes represent only a small part of the processes of social and economic change in Ujung Pandang, and by the same token, the concept of transfer of economic surplus is a relatively small part of a full explanation of underdevelopment. Yet, the social and geographic transfer of economic surplus can make a substantial contribution to an understanding of the broader processes associated with underdevelopment. There are 2 areas where more critical analysis can be directed and which will improve an understanding of the processes examined in this discussion: there should be more debate about the nature and theoretical significance of articulation especially transfers of value and surplus, and a greater input of empirical research to supplement this understanding; and it is necessary to focus more explicitly on the relations of production in the capitalist and precapitalist modes of production in the Indonesian city.     

SEX AND THE CITY: FEMALE LEADERS AND SPENDING ON SOCIAL WELFARE PROGRAMS IN U.S. MUNICIPALITIES

Scholars of urban politics often argue that cities will shy away from extensive funding of social welfare programs, as fiscal realities make developmental policies far more attractive. Despite these arguments, cities continue to fund social welfare programs. One possible explanation is that some local officials prefer funding welfare programs. This research demonstrates that the presence of a female mayor has a large, positive influence on the likelihood a city participates in funding social welfare programs and the amount of monetary resources a city dedicates to these programs. High levels of female representation on city councils and a mayor‐council form of government both interact with the presence of a female mayor to increase the provision and size of social welfare programs in cities.     

Agglomeration, productivity, and spatial spillovers across Chinese cities

This paper investigates the causal relationship between, and the determinants of, urban labor productivity and industrial agglomeration across Chinese cities. We extend the Ciccone and Hall (Am Econ Rev 86(1):54–70, 1996) production density model by distinguishing between the size of the industrial sector and the density of the urban economy in order to examine the effects of industry agglomeration and congestion on urban productivity. We also account for the endogeneity of industrial agglomeration and propose a simultaneous equation model to estimate the determinants of urban productivity and agglomeration. A spatial econometric analysis across 617 Chinese cities in year 2005 shows that the spatial concentration of industrial production is an important cause of higher productivity in large industrial cities and cities in neighboring regions, where higher productivity resulting from concentrated industrial production then leads to further agglomeration in these cities. Controlling for the size of the industrial sector, employment density has a negative effect on urban productivity. We conclude by briefly discussing potential policy implications of the empirical findings.     

ACCOUNTING FOR MUNICIPAL ECONOMIC DEVELOPMENT

Local economic development analysis typically emphasizes the metropolitan area, rather than municipalities, because it is the basic economic space, but it is not a strong unit of local government. Brief reference is made here to parallel research published elsewhere on a coordinated metropolitan development model and then focus shifts to a municipal model that evaluates the position, prospects, and potential of a given piece of space within the local economy. Three basic municipal economic roles—on occasion alternatives, complementary, or sequential—are itentified: (1) a site for export production contrasting goods and services), (2) a center for metropolitan trade and services (for business or households), and (3) as a preferred place of residence (for high or low income households). The central city of Cleveland is compared to its metropoltan area, using readily available Census data for the 32 largest metropolitan areas and their central cities. Other Census data on the age distribution of housing and residential relocation between central cities and suburbs (disaggregated by occupation, education, and income) are examined as additional examples of the kind of data that can and will be integrated into this three-path muncipal model. The ultimate objective is to link that metropolitan (economic) model and this municipal (policy) model into a broad decision-making framework for local economic development policy and planning.     

Scarcity and Abundance: Urban Agriculture in Cuba and the US

In urban agriculture, there is a direct connection between scarcity and abundance: with the threat of food shortages so often acting as an effective trigger for food-growing enterprises. Produce can also be grown with few or limited resources. André Viljoen and Katrin Bohn of Bohn&Viljoen Architects juxtapose the experience of the organopónicos, or market gardens, in Cuba, which have proliferated since the US trade blockade of the 1990s and ensuing fuel shortages, and more recent experiments in food production in North American cities that are learning from their example.