Mode Choice,Commuting Cost,and Urban Household Behavior*

Abstract. In this paper, we extend the partial equilibrium urban model of DeSalvo (1985) to include mode choice. DeSalvo demonstrated that the urban model of Muth (1969) was robust to the extension to leisure choice. We show that the model is robust to mode choice as well. In addition, we derive the comparative static results that commuters choose higher speed modes for longer commutes, at higher wage rates, with greater tastes for housing, and with lower housing prices. Also, for a given distance commuted, we derive the comparative static result that commuters chose shorter duration commutes at higher wage rates. Whereas it is typically assumed that marginal commuting cost is positive and non‐increasing with distance, we derive these results. Moreover, we derive the results that marginal commuting cost rises with an exogenous increase in housing price and falls with increased tastes for housing. We also explore the effects of exogenous commuting‐cost changes on the endogenous variables of the model. The remaining comparative static results on housing consumption and location are qualitatively the same as in DeSalvo.     

A Spatial Economic Analysis of Urban Land Use and Obesity*

Abstract. We analyze an urban spatial model to examine the possible link between urban land use and obesity. Households maximize utility defined over housing, weight, and food subject to a fixed time budget allocated to commuting, calorie expenditure, and work. Our model explains the observed correspondence between high obesity rates and low development densities, but implies that these are determined endogenously in a spatial market equilibrium. We study the sorting of residents by attributes such as income, initial weight, and weight preferences, and examine the impacts on weight and density of urban design modifications that lower the costs of calorie expenditure.     

The Influence of Local Urban Containment Policies and Statewide Growth Management on the Size of United States Urban Areas*

Abstract. In an attempt to slow the consumption of urban land for a given population, and the negative outcomes thought by some to be generated by such sprawl, regulations in the form of (i) the local imposition of urban containment policies that restrict or prohibit the amount and/or the type of urban settlement beyond a certain line and (ii) the statewide enactment of mandatory growth management requirements for all local governments have been enacted in the United States. This paper describes a regression‐based analysis that finds that different forms of these policies are achieving their desired goal of shrinking the square mile size of an urban area. A comparison of the influence of the various forms of urban containment and growth management policies with other “natural evolution,”“flight from blight,” and “fiscalization of land use” factors that also influence the square mile size of an urban area is made, and policy implications are offered.     

永远的田野

一、八十年代是“现代化”和“文化讨论”的年代,那个时代的学生看起来总有一点“反叛”的样子,基本心态就是“重新评价一切”。一种急于了解“真相”的冲动,造成了对“田野”的持久的偏爱。     

Geopolitical Force Fields

An entropy-maximizing model of the geographic deployment of power by states is derived from a minimal set of assumptions about the system's operation. The outcome is a production-constrained gravity model. This is manipulated to yield the general expression for the boundary between the spheres of influence of competing powers. Even in this simplest of forms, the model provides a logically consistent theoretical framework with which to view the outcomes of major geopolitical changes. The elaboration and disaggregation of the model to tackle finer adjustments would not be difficult.     

Spatial Price Discrimination in Two-Dimensional Competitive Markets

Intuition suggests that firms that can apply price discrimination make higher profits than firms that are restricted in their pricing policy. In this paper, we show that, in general, this is not the case. In the framework of a two-dimensional spatial model with elastic demand à la Lösch, we further investigate the interplay of transport costs, competition, and price policy. One of our results is that under realistic specifications of parameters each firm gains a monopolistic area in the center of its market that has the same shape as the entire market, but with a convexly or concavely distorted separating line, depending on the extension of the market.     

亲密接触大自然--俄罗斯赤塔之旅散记

2004年7月,全国党报社长、总编辑研讨会在满洲里召开,会议安排了去俄罗斯赤塔市采访观光。三天的赤塔之行,让人感受最深的是俄罗斯民族对大自然的呵护和亲近。呵护自然由满洲里至赤塔480公里的旅程,可谓是地广人稀。沿途所见的30余个市镇村落,千户以上不过二三,多是百余户、几十户。彼此隔着几十或是十几公里的茫茫荒野林海,大多没有人烟、牛羊、耕地。由于人烟稀少,即便是公路两侧的荒草,也十分茂盛,厚厚的,一层盖着一层,将地面遮掩得严严实实;在林区,路边的原始树木也比比皆是。在拥有丰富自然资源的同时,是俄罗斯人对大自然的倍加珍惜与…     

从水田考古发现看畦田的发生

我国水田考古始于20世纪90年代初.根据目前出土的史前时期的十多处200多块水田遗迹进行总结,史前水田以小型和不规则形的平底浅坑式田块为主,都具有较为完善的灌溉体系.根据湖南澧县城头山、浙江余姚施岙和余杭茅山遗址发现的水田中的田埂形态分析,我国以方便灌溉为首要目的 的畦田萌芽于距今6000年左右,以生土田埂界隔地下田面为标志;成熟于良渚文化中晚期,以人工田埂规划地面田为标志.畦田是水稻种植过程中的一大发明,之后的水田仍然延续着内部作畦的方法,并对后世北方地区的灌溉农业产生了深远的影响.     

Urban,Suburban, and Exurban Sprawl in the Rocky Mountain West: Evidence from Regional Adjustment Models*

Abstract. This article adapts a regional adjustment model to examine land use change in the Rocky Mountain West region of the United States. Three interrelated questions motivate the research. How does the proliferation of urban, suburban, and exurban sprawl in the Rocky Mountain West relate to the population and employment growth process? Are population and employment endogenously determined there? And what does this imply for the sustainability of economic development in the region? Through a series of regional adjustment models, the empirical analysis links population and employment growth in the Rocky Mountain West to explicit spatial outcomes and delivers substantive evidence of endogeneity between the two. The results suggest that the long‐term prosperity of the region depends on the preservation of the high quality of life it offers, and that greater intergovernmental coordination, careful infrastructure planning, and attention to the character of its economic structure may help to accomplish this. Future research should focus on looking deeper into certain explanatory variables used in this analysis and on developing a better picture of what the spatial equilibrium that regional adjustment models emulate may look like.     

Evaluating Tobler's Migration Vector Fields

In the past decade Tobler has provided an innovative cartographic presentation of migration flows. The central theme of this research has been to utilize detailed migration data to reveal the underlying structures of migration flows. Even though the analyses are not explanatory models of migration exchanges, the application of these techniques to migration flows over time and across different spatial scales provides a visual generalization of often extremely complex flows. The application of his techniques at two spatial scales for the Netherlands illustrates both the strengths and weaknesses of migration force fields for the analysis of migration.