A NOTE ON THE STABILITY PROPERTY OF SPATIAL COMPETITION*

ABSTRACT. Our study extends the standard comparative static analysis to allow for dynamic aspects of equilibrium in spatial competiton. We investigate dynamic stability properties via the Routh-Hurwitz criterion. Nontrivial equilibria in the so-called Löschian, Hotelling-Smithies, and Greenhut-Ohta models are shown to be stable even under heterogeneous cost conditions among competing firms, conditions not considered hitherto. We can thus provide powerful support to the comparative static analyses which can only be developed via equilibrium concepts with stability properties.     

A NOTE ON THE DIFFERENTIAL THERMAL ANALYSIS OF ARCHAEOLOGICAL CERAMICS

Evidence is presented that the clay in ancient ware fired at a temperature below 700–800°C becomes rehydrated over the millennia, such that it behaves somewhat like an unfired clay, rendering DTA a useful tool in identifying the clay minerals present. More recent samples can be artificially rehydrated by heating in a steam autoclave.     

A NOTE ON NEIGHBORHOOD SIZE AND THE MEASUREMENT OF SEGREGATION INDICES*

This note examines neighborhood segregation measures with respect to size and validity. Conventional measures, while related to within-neighborhood homogeneity, are not necessarily related to neighborhood size. An empirical test examines racial segregation for Baltimore in 1970 and 1980 using both census tract and specially formulated neighborhood aggregates. For both years, and for all measures of segregation, the values and trends are essentially unchanged by the level of aggregation.     

A COMPARATIVE ANALYSIS OF TIME SERIES APPROACHES TO MODELING INTERSECTORAL AND INTERCOUNTY EMPLOYMET LINKAGES IN RURAL REGIONAL LABOR MARKETS*

ABSTRACT. The performance of five criteria for identifying significant interregional labor market linkages is compared. The criteria suggest differential model specifications based on the implicit tradeoff between parsimony and specification bias. Models were specified using: Akaike's final prediction error; Schwarz's Bayesian information criterion; an input-output model; Aoki's time series algorithm; and a combined input-outputi/time series approach. Models of the changes in monthly employment for twelve industries in six regions in northeastern Utah were specified using each criterion. Models based on Schwarz's criterion and the input-output criterion were preferred to those based on other criteria.     

基于GIS的中国省际人口迁移流的空间特征分析

文章基于中国第五、六次人口普查与2005年1%人口普查数据资料,采用流数据分析方法,运用GIS空间分析技术,选用省际人口迁移的最大联系线、最大迁出流、最大迁入流、期望线、迁移效率、粗迁移率等方法系统地研究了我国1995-2010年间省际迁移的时空动态特点及其区际联系。结果表明:全国省际人口迁移的流动性不断增强,东部地区更明显;省际最大人口迁出与迁入流反映了中国省际区域间空间相互作用整体框架,全国大致可以分为3个人口吸引片区和5个辐射片区;省际最大净迁移流主要分布在东南沿海地区,中、西部地区分布较少,其空间分布与各省的MEI_(i)指数密切相关。