A Dynamic Model of Growth in a Central Place System

A model is developed in which the change in the population distribution of a region is linked to the employment pattern, and this latter in turn to the population distribution through the concepts of central place theory. The result is a dynamic model of interacting urban centers in which the fluctuations (the exact history) of the system play a vital role, and with which the effect of an infrastructure decision can be estimated in the long term.     

Population Oscillations in a Nonlinear Migration Model

The purpose of this paper is to prove the existence of Hopf bifurcations in Sheppard's generalized dynamic migration model. Hopf bifurcations appear as a result of structure changes in the system. First, we deal with the general case of H cities. Then, the case of two cities is dealt with.     

Residential Mobility Patterns and Population Redistribution within the City

A residential change model is derived that allocates migrants to housing vacancies using a Luce-type choice process. The residential change model is then used as the basis for a small area forecasting model designed to predict changes in the size and composition of the population residing in designated areas of the city.     

论转型期英国人口迁移模式的变化

转型期英国人口迁移以17世纪中叶为界先后形成了生计型迁移和改善型迁移两种模式。17世纪中叶以前,随着人口快速增长而出现乡村人口过剩,许多人为生计所迫,在原住地推力和城市拉力的双重作用下形成了生计型迁移模式。这一时期人口迁移具有相当的盲目性和不确定性。17世纪中叶以后,人口增长减速,经济地理布局日趋均衡,城市拉力作用减弱,人口迁移走向地方化和有序化,从而形成了改善型迁移模式。转型期英国人口迁移模式的变化深刻影响到向近代社会转型的历史进程。     

A Location-Allocation Model of Lösch's Central Place Theory: Testing on a Uniform Lattice Network

This paper develops a location-allocation model of Lösch's central place theory that maximizes the number of firms that can coexist in the market, subject to range, threshold, hierarchy, and other constraints. F.o.b. costs, economies of scale, and elastic demand are included. Consumer behavior postulates concerning the “nearest center hypothesis” and the “indifference principle” are formulated as nonlinear constraints but not used during solution. Methods are developed for simulating the continuous, infinite plain with a discrete, bounded network by use of an outer overflow network and a symmetrical market area constraint. The model is tested by applying it to a uniform lattice network and comparing the results to the expected pattern of nested hexagons. Solutions consistent with the k = 3, 4, and 7 patterns are generated by changing threshold values. However, remaining inconsistencies appear to be due to the inability to express the consumer behavior laws as linear constraints, to the bounded and discrete nature of the network, and to the objective function being the sum of integer variables. The long-run purpose of developing and validating a location-allocation model of a location theory is to use it to relax the theory's restrictive assumptions and to apply the theory to nonuniform regions.     

A Model to Relate the Size of the Central Business District to the Population of a City

A set of dynamic models of CBD growth are developed. They hypothesize that growth rates depend upon the population growth rate together with the increasing unwillingness of people to travel to the city center as city size increases. A prediction of the model is that absolute decreases in CBD size can occur associated simply with population growth rather than technological change as is usually postulated. The models are tested using retail sales data for the United States. Good predictions are generally found, especially when the unique CBD of New York City is removed from the data set. However, the model which has the greatest theoretical validity relative to central place theory does not have the best fit to the data. Implications of this are discussed, along with those of utilizing transformations in regression models.     

A Hierarchical Market Model of International Trade

The characteristics of hierarchical trade flows, when placed in the context of differentiated markets, can provide some insight into the underlying bases of contemporary international trade. A model that relies on differentiated market theory and hierarchical market theory is developed. Trade characteristics derived in the model, concerning the frequency and value of trade, are empirically tested. Empirical results indicate that the model provides a useful framework for the analysis of contemporary international trade.     

Dynamic Central Place Theory: Results of a Simulation Approach

A dynamic central place theory is formulated as a simulation model in which retail activities, described by cost equations, and consumers, described by spatial interaction equations, interact to generate a central place system. The behavior of the model is then examined. Simulation results show that the basic character of the system—whether it is agglomerated or dispersed—depends primarily on a single parameter in the interaction equation, and only secondarily on the specification of the cost function. The results are highly robust in that they are largely independent of the initial sizes and locations of centers, and even independent of the type of interaction equation used. The patterns generated appear plausible.     

The Place of Population Geography in the System of Population Sciences

The area of research that is considered the proper domain of population geography is defined. In addition to an areal approach to the analysis of various aspects of population, such as growth, structure, migration and settlement patterns, there is great need for synthetic regional population studies, integrating all aspects of population within a particular territory. Causal relationships must be explained and the study of population must be related to the study of economic location.     

Prospects of Population Migration in the USSR

The author offers a methodology for estimating inter-regional population flows in the USSR for the next quarter of a century. The method is based on expected regional manpower needs related to a model of the future distribution of production. Corrections are made for expected regional differences in the need for live labor [depending on the level of mechanization], in rates of natural increase and in the degree of mobility of the population of certain regions.     

The Influence of Ethnic Factors on the Territorial Redistribution of Population

Although a number of non-Russian republics of the Soviet Union (Central Asia, Transcaucasia, Moldavia) are labor-surplus areas, ethnic factors operate against migration of these national groups not only to labor-deficit regions in the RSFSR but even to cities of the non-Russian republics. Instead, Russians make up most of the migrants to labor-deficit regions (European North, Siberia, Far East, Kazakhstan) and to the cities of non-Russian republics. A system of measures in proposed to correct the situation.