Price Variation in Spatial Oligopolies

The “geography of price” is being given renewed attention by geographers and economists. This paper examines spatial price variation in both unbounded (circular) and bounded (linear) one-dimensional markets. Firms compete for consumers in the short run by adjusting price until the Bertrand equilibrium is reached in the market. While firms act as spatial oligopolists in specific market segments, the profit-maximizing price of any given firm depends directly and indirectly upon the spatial-economic properties (locations, marginal costs) of all other firms in the market.     

The Spatial Search Problem: Structure and Complexity

The paper discusses structure and complexity of the spatial search problem. From a set of assumptions it derives a rather general version of the spatial search problem and investigates some of its fundamental properties. Most importantly, the paper shows that the decision problem corresponding to the spatial search problem in this general version is NP-complete.     

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.     

Dimensions of Spatial Price Dispersion Before and After the Crash of 1929

The spatial and temporal patterns of prices are analyzed over the 1919–40 period. Arguments are made for the distinctiveness of different economic episodes, including the crash of 1929, in terms of their local price effects. Nevertheless, it is also shown that the variability between cities and between components of their price series declined through the early 1940s. Alternative conceptions of spatial price systems are introduced, and due regard is also given to the structure and interpretation of city CPI data. Implications are drawn regarding the proper design of a theory that would explain the observed patterns of spatial price dispersion. This larger project is left, however, to another time.     

In Search of the Middle Ground: Quantitative Spatial Techniques and Experiential Theory in Archaeology

In March 2011, a conference was held at the University of Aberdeen, Scotland, focusing on the possibilities and potentials of combining quantitative spatial studies with more human-centred and theoretically explicit approaches to past landscapes. This short introduction outlines the main themes and goals of the conference and the resultant papers, published here as a special issue.     

Desertification Processes and the Search for Solutions

Abstract

This paper reviews the evidence of desertification as reported in the scientific literature by ecologists, meteorologists, hydrologists, archeologists and various other disciplines. There is not as yet full agreement as to the extent and causes of this phenomenon. World wide climatic changes have been cited as causative factors, but the influence of man is still considered by most investigators as the dominant cause, possibly exacerbating cyclic climatic changes. Deserts, semi-arid and marginally productive areas vary greatly in extent and for different reasons.

Results of research and development have indicated that the enlightened intercession of man can contain and reverse this process. Sound management and conservation of existing land and water resources seem to be the basic needs and are perhaps the easiest technology to transfer to the desert farmer and nomad. The introduction of drought-hardy tree and bushes of economic value to bind drifting sand dunes and to regenerate overgrazed pastures have also proven their value. Recent research has shown the possibility for better utilization of water resources including brackish water for irrigation of agricultural crops.

Many other fields of technology are being applied to this problem, but the major focus will undoubtedly have to be on man himself and there has been some research on social organization, nomadism and sedentarization, technology transfer, population control, directions of education and a host of similar problems. Much more work will have to be channelled into this direction, however, if real progress is to be attained.     

寻访大禹的足迹

2007年6月12日至18日,历时7天,青海省政协副主席鲍义志带领民和回族土族自治县分管旅游的副县长安永辉、县社会发展局和旅游局的负责同志     

Asymmetric Entrant Locaiton with a Discrete Consumer Distribution: Spatial Price Discrimination Versus Mill Pricing

In this paper I examine the profit-maximizing locations of entrants. Suppose that firms practice spatial price discrimination and consumer locations are discrete, such as five equally spaced towns on a roadway. With completely inelastic consumer demand an entrant between two existing firms is often indifferent between the symmetric (central) location and a continuum of asymmetric (noncentral) locations. However, downward-sloping consumer demand often causes the entrant to strictly prefer either of two asymmetric locations to any other location. These results are very different from those found in mill-pricing (free-on-board or f.o.b.-pricing) models.     

探寻美国革命的思想渊源——保罗·拉厄的《古代和现代的共和国》与共和主义范式之争

保罗.拉厄的《古代和现代的共和国:古典共和主义与美国革命》以共和主义为主题探讨了古典共和主义与美国革命的关系。拉厄力图开辟研究美国革命和建国的新路径,对共和学派的主旨和研究方法提出修正。《古代和现代的共和国》不仅体现了拉厄对共和学派主将波科克的挑战与批判,而且反映了20世纪60年代以来美国早期史研究领域的派别之争以及史学理论和研究方法的变动。他同时受到施特劳斯学派和自由主义传统史学的影响,卷入了施特劳斯学派与共和学派之间,"新洛克派"与共和学派之间的学术辩论。但他又不是完全照搬两派的主旨和研究方法,而是在两派的核心观点和研究方法基础上提出了新见解。