Probing A Traffic Congestion Controversy: A Comment

Ohta (2001) claims to have resolved a die-hard controversy on traffic congestion modeling by defining an inverse aggregate demand function that has traffic density as its argument—in Ohta's terminology the 'primitive term.'Using this demand function, Ohta shows that 'hypercongestion' may very well be an optimal stationary state. This contribution argues that at least if what road users demand is completed trips, and if time spent on the road while traveling implies a cost, then Ohta's approach is fundamentally flawed. Also the conclusion that hypercongestion can be optimal is no longer valid.     

Variable Residential Density: Optimum Traffic Density and City Size

In this paper we derive the optimal allocation of land between transportation and housing uses in an outer ring of a circular city, where the net population density is a constant, an exponent-decaying, or a power-decreasing function. We are also able to show that, under these circumstances, at no point in the optimal solution is all the land allocated to transportation use, proof that is, unlike previous work, independent of the solution of the same problem in the inner ring (Central Business District).     

A Continuous Model of Traffic Flow

Traffic flow over continuous space is analyzed in an abstract one-dimensional city. A negative exponential attraction function, a quadratic exponential distribution of trip origins and a negative exponential distance-decay function are combined, and expressions are derived for traffic flow between arbitrary intervals in the city. With appropriate choice of the trip-origin function, the model may be applied to single and multipurpose trips. The resultant “contact fields” for individuals are briefly described, and the main results comprise algebraic approximations for aggregate flows between intervals. Numerical examples are given.     

当代美国大都市区交通拥堵的治理措施

20世纪70年代以来,交通拥堵已经成为美国大都市区最严重的社会问题之一,因而受到各级政府和社会各界越来越多的关注。为了解决交通拥堵及其产生的社会危害,美国各级政府、民间团体和私人企业等采取了一系列措施,比如扩建公路、发展公共交通、推行共同乘车计划、建立高密度混合开发且公交友好的社区等。然而实施这些措施并没有有效地缓解交通拥堵问题,其根本症结在于汽车、公路和城市低密度蔓延这三者间的互动关系没有得到根本的改善。     

当代美国大都市区的空间结构特征与交通困境

第二次世界大战后美国大都市区的交通拥堵现象越来越严重,而且从20世纪70年代以来出现了新的发展趋势,即交通拥堵由原来的中心城市不断向郊区延伸.美国大都市区交通拥堵的原因深深地植根于大都市区的空间结构之中,其中包括郊区的低密度蔓延、住宅和就业的失衡、社区土地利用模式的单一性、郊区社区的空间设计和道路系统等.由于这些结构性问题十分难以克服,美国大都市区的交通陷于困境之中.     

Agglomeration Diseconomies of Traffic Congestion and Agglomeration Economies of Interaction in the Information-Oriented City

This paper presents a partial equilibrium model of land, labor, and transportation markets in an information-oriented city with traffic congestion of commuting and agglomeration economies of interaction. We derive the equilibria by numerical computations using specific utility, production, and congestion functions. The laissez-faire equilibrium is compared with the optimum. In contrast with the results of many previous papers, at the optimum the CBD becomes compact and the city more suburbanized than the laissez-faire equilibrium. We also analyze the effects of a Pigouvian tax system and subsidies on the spatial structure in the city.     

China's Exchange Rate Controversy: A Balanced Analysis

A noted American authority on China's economy and monetary policy presents a statistical as well as theoretical analysis of a variety of perspectives on the controversy surrounding China's currency, basing his paper on both. The author provides the historical background and comprehensive summaries, focusing on different viewpoints about whether China's currency is undervalued, and thus may contribute to global imbalances. In the paper, he divides observers involved in the controversy into two main camps, namely the ones who find China's trade balances to be sensitive to price effects through exchange rate adjustments and those who emphasize other factors as bearing the responsibility for China's large surpluses, including the U.S. credit bubble emerging before the global financial crisis, as well as a version of Dutch disease.     

Congestion Pricing and Demand Management: A Discussion of the Issues

This article reviews the political, technological, and economic issues involved in the formulation of congestion pricing policy. Increased urban congestion combined with increasingly scarce resources is making policymakers consider congestion pricing as an alternative to expanding highway capacity. Past experiences with congestion pricing and other types of demand management are discussed in an attempt to identify problems policymakers may expect to encounter in the US.     

因相近而区分：“问题与主义”之争再认识之一

“问题与主义”之争为时不长,却触及一些时代关注的焦点,反映出“五四”前后中国思想界异常丰富而活跃的动态,特别是各种流派混杂难分、阵线混淆的重要特征。关注“社会”的革命或改良是时代的共同点。包括安福系在内的朝野各方都以为不可避免。这样的朝野相似性使“新舆论界”一边希望有所“区分”,以确立自身的特性。有些后来以为冲突的观念,对当时当地的当事人而言,未必就那样对立,反有相通之处。胡适和李大钊的相关言论在一段时间里共同成为年轻一辈的思想资源,提示着这一争论未必像后来认知的那样意味着新化人的“分裂”,或即使“分裂”也不到既存研究所论述的程度。     

What Carl Schmitt Picked Up in Weber's Seminar: A Historical Controversy Revisited

The intellectual relationship between Carl Schmitt and Max Weber has been a point of controversy for at least half a century. At the 1964 convention of the German Sociological Association, in honor of Weber's centenary, Schmitt was famously referred to as Weber's “legitimate student.” This article uses the chapter Schmitt specifically wrote for an edited volume in Weber's memory, published in 1923, as the starting point for juxtaposing the two scholars, and then expands the analysis to encompass a range of sources and commentaries. The comparison focuses on the approach of each of the two scholars to methodology and didactics, theory and conceptual use, as well as to the society/social science nexus. The article concludes by arguing that Schmitt performed a double rhetorical move: while styling himself as Weber's student, he then drew on that authority to assault Weber's liberalism and concept of scientific integrity.     

Sovereignty,Risk and Biotechnology: Zambia's 2002 GM Controversy in Retrospect

The southern African food crisis of 2002 led to one of the most significant controversies over the use of genetically modified (GM) crops in the developing world to date. Zambia's staunch opposition to GM food aid during the crisis is still frequently used as a reference point in debates over GM seed technology in agricultural development, and the morality of advanced biotechnology. This article re‐examines the controversy and its contemporary relevance using oral history interviews with key scientists, policy makers and development practitioners engaged in debates and decision‐making processes in Zambia in 2002, alongside a review of discourses in the Zambian press. The author argues that, rather than different perceptions of health and environmental risks derived from GM crops, it was questions of sovereign regulatory control of technology in a context of diminished state capacity — and the decline in the Zambian state's capacity for agricultural science research in particular — that played a central role in shaping anti‐GM attitudes. In addition, trust in the arguments of GM advocates was diminished by communication efforts which treated Zambian scientists and policy elites as a lay rather than an expert audience.