A Hierarchical Migration Model of Population Redistribution within a Central Place Hierarchy

A simple hierarchical migration model is proposed as a mechanism for the redistribution of population within a Christaller central place hierarchy. Given a predefined functional hierarchy, the migration process causes any initial population distribution to converge to an equilibrium distribution. Under certain special conditions, the equilibrium is identical to a central place population distribution derived from economic base concepts.     

Migration and Occupational Choice among Young Labor Force Entrants: A Human Capital Model

Interregional variations in the conditions for entering the labor force are investigated by analyzing interdependencies between migration behavior and occupational choice for young labor force entrants. The human capital framework indicates that occupational choice depends on the costs and returns associated with entering various occupations, and that interregional variation in these costs and returns is a major reason for migration. Occupational choice and migration behavior will be interdependent if the costs and returns for particular occupations vary over local labor markets, relative to other occupations, and patterns of interdependence between the two decisions are analyzed, using a model of the joint choice of occupation and location. An empirical analysis of occupational choices and migration behavior for young people who entered the U.S. labor force in the 1975–80 period indicates that the odds for entering professional or managerial occupations varied with origin and migration behavior in systematic ways.     

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.     

旅游者决策行为研究

本通过对旅游决策行为的初步研究,勾勒出旅游决策的基本行为特征,并在此基础上构建了旅游决策行为模型。通过对这一行为模型的分析,得出了影响旅游决策行为的相关因素及其内在关系。     

Land Markets in the Harris-Todaro Model: A New Factor Equilibrating Rural-Urban Migration

Recent research in the Harris-Todaro (HT) tradition has added an important new element to the model by incorporating an urban land market. Brueckner and Zenou (1999) (hereafter BZ) argue that a model where migration equalizes expected wages between city and countryside may overlook another important force that equilibrates the process of rural-urban migration. This force is the migration-induced rise in the urban cost of living, which occurs principally through escalation of urban land rents as the city population expands. Land-rent escalation, which tends to limit rural-urban migration, provides an important additional force that may help determine city sizes in developing countries. The present paper provides a simpler alternative to BZ's analysis by assuming that urban residents smooth their income as they cycle between formal and informal employment. This allows migration decisions to be based on the expected wage, as in the usual HT framework, in a model that includes a land market. The analysis shows that this modified framework generates results slightly different from those of BZ.     

The Timing of Angel Mounds Palisade Construction A Search for the Best Chronological Model

Abstract

Angel Mounds was a heavily fortified Mississippian settlement with several discrete palisades. Although the palisades were identified early on, the construction sequence has remained elusive because the construction episodes do not have stratigraphic relationships with one another. Recent work at the site reexamined old test excavations and collected new material for radiocarbon dating. AMS dating yielded a suite of new dates from palisade contexts. To refine the construction sequence, five Bayesian chronological models were constructed for palisade building. These models indicate that palisades were first built at Angel Mounds sometime between A.D. 1278 and A.D. 1410, which precedes or coincides with regional depopulation in the lower Ohio River valley. These results further indicate that palisade building at Angel Mounds may be a consequence of external competition and conflict caused by resource-induced stress resulting from deteriorating climatic conditions.     

Two-Way Migration in a Model with Identical Optimizing Agents

The simplest migration models based on maximizing behavior assume movement toward more desirable locations, and therefore ignore the large portion of moves in the "wrong" direction. Based on a model with identical, utility-maximizing agents, the analysis below shows that changes in relative location attractiveness can cause many migrants to move against the dominant stream. Even when the population distribution is stable and variation in wages and prices across locations reflect compensating differentials, so locations are equally attractive, individuals choose to move between locations, spending parts of their lives in different locations. These results stem from the role of consumption opportunities in migration decisions, highlighting processes that have been largely ignored.     

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 Messenger For the Han and Tibetans

The ＂Tashideleg for Beijing and Tibet＂ activity started at the end of 2004. With the help of the Haidian District Children＇s Work Committee the Lhasa Chengguan District Children＇s Work Committee and the China Tibet Information Center, 25 primary schools including the Lhasa Lodui Primary School and the Beijing Shuangyushu Central Primary School paired off in a Hand-in-Hand relationship. On May 26, 2005, 16 teachers and students from Lhasa Chengguan District came to Beijing to participate in exchange activities for one week with the help of Haidian District children.     

罗布泊边缘疯狂的寻鸟之旅

<正>寻鸟的过程中有酸甜苦辣,有惊魂动魄,但我都义无反顾勇往直前。一切起源于这样的一段话:“做为‘鸟人’,你能拍到鸟,说明你在认真做了一件事;你能拍好鸟,说明你把拍鸟的相机参数和方法掌握得很好了。如果你能拍好某种鸟系列的作品,说明你是一个真枪实干的拍鸟高手;如果你能通过手中的摄影器材,拍出鸟儿的内心世界、生活习性、生存现状以及通过它们的食物链、周边植被,或在它们周边所出现的天敌及鸟儿迁徒等能判断出它们的方位,那真要给你点个赞,你是真正值     

The Welfare Economics of Rural-To-Urban Migration: The Harris-Todaro Model Revisited

In this paper we extend the Harris-Todaro model of rural-to-urban migration to include urban agglomeration effects, some urban real wage flexibility, and a government budget constraint. Without employment subsidies laissez-faire migration is excessive unless real wage flexibility and agglomeration effects are high. Laissez-faire migration is too low compared with the first-best outcome supported by a subsidy, if its financing involves no costs. Simulations suggest that such a program would imply a substantial increase in taxation. If, as seems likely, an increase of this magnitude involves economic costs then the optimal outcome falls well short of first-best.