MIGRATION AS A WAY TO DIVERSIFY: EVIDENCE FROM RURAL TO URBAN MIGRATION IN THE U.S.

This paper extends the utility maximization model of migration by introducing income and unemployment‐related uncertainties as determinants of utility, and analyzes the effects of the informational advantages of migrants. The paper maintains that migration would expand an individual's economic choices and opportunities and allow diversification. Consequently, diversification advantages influence the location decisions of migrants, an effect captured by the correlation of incomes at the origin and potential destinations. We use the discrete choice model based on random utility maximization as the framework for our empirical investigation of migration from the United States rural to urban counties. This paper takes advantage of an equivalent relation between the conditional logit model and Poisson regression to study the migration decisions using aggregate data among a large set of spatial alternatives. The results show that the diversification concerns have significant effects on location decisions of the rural‐urban migrants in the United States.     

MODELING RESIDENTIAL CHOICE*

ABSTRACT. This paper presents a new approach in the modeling of residential choices for simulation purpose. The originality of the approach resides in the way recent developments in stochastic choice models are combined with deterministic mathematical programming which allows to define an equilibration process for simulation. In that respect, ex ante probabilities of housing choice based on random utility maximization under perceived constraints are distinguished from ex post probabilities of choice that respect supply constraints. The proposed model is tested on the Montreal Metropolitan Region, and a few simulation results based on a scenario of population aging and decrease in household size are analyzed.     

THE OPTIMAL PROVISION OF A CENTRAL PARK IN A CITY*

In this paper, I examine the conditions and decision rules pertaining to the efficient provision of a central park in a city (provision that must satisfy the Samuelson condition). An interesting finding is that an additional opportunity cost that results from competition with residential use must be included to determine the efficient size of a central park. An efficient central park is larger in a city with public landownership than in a city with absentee landownership. Profit maximization and population maximization can be used as decision rules to determine the efficient provision of a central park in both an open city with absentee landownership and one with public landownership. The net benefit of a central park in a closed city with absentee landownership is reflected not only in the land rent or profit, but also in the utility level, while that of a closed city with public landownership is fully reflected in the utility level. It is not feasible to determine the efficient size of a central park for a closed city with either absentee or public landownership solely based on observable market information.     

On the Logit Approach to Competitive Facility Location

The random utility model in competitive facility location is one approach for estimating the market share captured by a retail facility in a competitive environment. However, it requires extensive computational effort for finding the optimal location for a new facility because its objective function is based on a k -dimensional integral. In this paper we show that the random utility model can be approximated by a logit model. The proportion of the buying power at a demand point that is attracted to the new facility can be approximated by a logit function of the distance to it. This approximation demonstrates that using the logit function of the distance for estimating the market share is theoretically founded in the random utility model. A simplified random utility model is defined and approximated by a logit function. An iterative Weiszfeld-type algorithm is designed to find the best location for a new facility using the logit model. Computational experiments show that the logit approximation yields a good location solution to the random utility model.     

Modeling Micro-Spatial Employment Location Patterns: A Comparison of Count and Choice Approaches

This article studies employment location patterns in the Puget Sound Region of Washington State at a micro level of geography. Traditional discrete choice modeling using multinomial logit (MNL) models may be problematic at a micro level of geography due to the high dimensionality of the set of alternative locations and the likely violations of the independence from irrelevant alternatives (IIA) assumption. Count models are free from the IIA assumption and, unlike logit models, actually benefit from large numbers of alternatives by adding degrees of freedom. This study identifies the best-fitting count model as the zero-inflated negative binomial (ZINB) model, because this model more effectively addresses the large number of cells with no jobs and reflects a dual process that facilitates the identification of threshold clustering effects such as those found in specialized employment centers. The estimation and prediction results of ZINB are compared with those of MNL with a random sampling of alternatives estimated on an equivalent data set. The ZINB and MNL models largely agree on major trends, with the ZINB model providing more insightful details, but with less capacity to predict large count situations.     

DISCRETE SPATIAL CHOICE MODELS FOR AGGREGATE DESTINATIONS*

ABSTRACT. In problems of spatial choice, the choice set is typically more aggregated than the one considered by decision-makers, often because choice data are available only at the aggregate level. These aggregate choice units will exhibit heterogeneity in utility and in size. To be consistent with utility maximization, a choice model must estimate choice probabilities on the basis of the maximum utility within heterogeneous aggregates. The ordinary multinomial logit model applied to aggregate choice units fails this criterion as it is estimated on the basis of average utility. In this paper, we derive and discuss a model which utilizes the theory underlying the nested logit model to estimate the appropriate maximum utilities of aggregates. We also demonstrate that the aggregate alternative error terms are asymptotically Gumbel, thereby relaxing the assumption of extreme value distributed error terms. This is accomplished with help from the asymptotic theory of extremes.     

Site Selection Problem and a Quasi-Satisficing Decision Rule

This discussion and overview of the site selection problem in the context of a quasi-satisficing decision rule combines two major rationality frameworks for locational decision making: utility maximization and bounded rationality. Their empirical and logical validity is discussed. From these concepts a quasi-satisficing rationality framework is developed and operationalized through a reference point approach. A quasi-satisficing decision-support procedure that involves a feed-back exchange of information between a decision maker and a computer-based support system is offered and a numerical illustration of this procedure is presented.     

Toward Conceptualizing Trip-Chaining Behavior: A Review

This paper critically reviews the existing literature on multiple-trip journeys, and clarifies the need for an improved conceptualization and modeling strategy. It also suggests different ways that trip chaining can be treated and a theory constructed. Exploratory studies, from the 1960s and 1970s, are briefly surveyed (Section I). While they developed the existence and complexity of travel patterns, they lacked any comprehensive theoretical framework. However, they were useful in that they supported the conceptual framework of various kinds of stochastic processes used by transportation scientists to replicate trip-chaining behavior (Section II). Scientists subsequently improved their conceptualization of the issue by grounding individual behavior on the principle of utility maximization. In this latter area the economists have emphasized theoretical concerns while transportation researchers have emphasized operationality (Section III).     

A TRANSLOG APPROACH TO CONSUMER SPATIAL BEHAVIOR*

With the view that travel behavior stems from the principle of utility maximization, in this paper I present a spatial translog demand model that accounts for interdependence among travel alternatives and that handles varying elasticities of substitution for various destination pairs. Using simulation as the mode of inquiry, this model describes the effect of spatial size, spatial configuration, and spatial substitution on spatial interaction. In addition to indicating how varying spatial sizes and configurations affect the average trip length and the trip making pattern, the simulation results also point out the possible effect of having spatially dependent locations in the system. Competing destinations increase the attractiveness of nearby locations, and complementary destinations reduce the impeding effect of space. The model is primarily relevant to the demand for shopping trips.     

多目的地ZTCM在旅游价值评估中的应用——以嘉峪关市为例

在旅行费用法(TCM)理论与应用的研究基础上,考虑游客出游时对于多个旅游目的地的选择以及旅行时间机会成本等问题,提出了多目的地ZTCM的基本思路与技术路线以及评估流程,并以嘉峪关市为例,对其国内旅游客源地划分为39个出游小区选定11个旅游目的地出游组合,利用门票价格及居民消费水平等指标计算各出游组合中嘉峪关市所占的旅游价值比例,对其进行合理的游憩价值评估。结果显示嘉峪关市2006年的旅游价值为7.384762亿元,其中国内旅游价值为6.227939亿元,海外旅游价值为1.156823亿元,与当年旅游收入4.62673亿元进行对比,可以发现嘉峪关市发展旅游的潜力比较大。此外,还对多目的地ZTCM的可行性以及评估结果进行了讨论分析。     

A NOTE ON BILATERAL MONOPOLY AND THE OPTIMUM LOCATION OF VERTICALLY RELATED FIRMS*

This note considers Blair, Kaserman, and Romano's conclusion (1989) that the only optimal solution in the case of bilateral monopoly is the joint profit maximization solution and examines the pattern of industrial location under joint profit maximization.     

STEADY-STATE LABOR TURNOVER AS OPTIMAL HOUSEHOLD BEHAVIOR*

ABSTRACT. Models of the firm with costly labor turnover and models of migration with location-specific consumption amenities are two standard explanations of the co-existence of persistent wage differentials with extensive labor mobility. Labor turnover models postulate a worker quit function where the quit rate is inversely related to the regional wage differential in the steady state. We use amenity-consumption models of migration to show conditions under which this postulate is consistent with household utility maximization. Our model extends standard amenity-consumption analysis by making the value of amenities contingent on the “state” of the household. These household states are defined in terms of demographic, education, and health characteristics and are assumed to follow a Markov process.     

The Pottery of Khirbet En-Nahas: A Rejoinder

Abstract

Smith and Levy (2008) have published an assemblage of pottery from the copper production centre of Khirbet en-Nahas in Jordan. Based on their interpretation of the ¹⁴C dates from the site and contra the accumulated knowledge on the ceramic typology of the Levant they argue that this pottery dates to the Iron I and Iron IIA, and that there was no later activity at the site. We show that much of the Khirbet en-Nahas pottery dates to the Iron IIB–C. We argue that the charcoal samples sent for radiocarbon dating originated from the waste of industrial activity at the site in the Iron I and Iron IIA, while the pottery came from a post-production activity in the Iron IIB–C — an activity that included the construction of a fort on the surface of the site. We propose that the fort was built along the Assyrian Arabian trade route, at the foot of the ascent from the Arabah to the Assyrian headquarters of Buseirah.     

COMPETITIVE FACILITIES: MARKET SHARE AND LOCATION WITH RANDOM UTILITY*

ABSTRACT. A new approach is proposed for calculating the expected market share. It is assumed that consumers patronize a facility according to a utility function, selecting the facility with the highest utility value. However, consumers'ratings of the utility components are stochastic by some random distribution. Therefore, the buying power of customers located at the same point is divided among several facilities. A probability that a consumer patronizes a certain facility can be calculated. Consequently, the expected market share by competing facilities can be estimated. This calculation is more than 1,000 times faster than repeating a simulation enough times to achieve a reasonable accuracy. The distance decay calculated using the new approach is approximately exponential. A procedure for finding the optimal location anywhere in the plane for a new facility that maximizes the market share is also introduced.     

Estimating Relative Standard of Living in the United States Using Cross-Migration Data

A new estimator links migration data to a random utility "voting with your feet" model to compare the relative living standards of pairs of regions. It is argued that this estimator has a firmer theoretical basis and uses migration information more efficiently than previous methods. An algorithm converts pairwise comparisons into rankings of the U.S. states for 1970, 1980, and 1990. The rankings indicate living standards were highest in the Northwest (1970, 1980) and the south Atlantic coast (1990). A nonparametric test suggests that the system was in disequilibrium in 1980 (probably due to energy price shocks), but near equilibrium in 1970 and 1990.     

Exploring the Use of Computer Vision Metrics for Spatial Pattern Comparison

Detection of changes in spatial processes has long been of interest to quantitative geographers seeking to test models, validate theories, and anticipate change. Given the current “data-rich” environment of today, it may be time to reconsider the methodological approaches used for quantifying change in spatial processes. New tools emerging from computer vision research may hold particular potential to make significant advances in quantifying changes in spatial processes. In this article, two comparative indices from computer vision, the structural similarity (SSIM) index, and the complex wavelet structural similarity (CWSSIM) index were examined for their utility in the comparison of real and simulated spatial data sets. Gaussian Markov random fields were simulated and compared with both metrics. A case study into comparison of snow water equivalent spatial patterns over northern Canada was used to explore the properties of these indices on real-world data. CWSSIM was found to be less sensitive than SSIM to changing window dimension. The CWSSIM appears to have significant potential in characterizing change and/or similarity; distinguishing between map pairs that possess subtle structural differences. Further research is required to explore the utility of these approaches for empirical comparison cases of different forms of landscape change and in comparison to human judgments of spatial pattern differences.     

The Colocation Quotient: A New Measure of Spatial Association Between Categorical Subsets of Points. 协同区位商：点集分类子集间空间关联性的新度量标准

This article presents a new metric we label the colocation quotient (CLQ), a measurement designed to quantify (potentially asymmetrical) spatial association between categories of a population that may itself exhibit spatial autocorrelation. We begin by explaining why most metrics of categorical spatial association are inadequate for many common situations. Our focus is on where a single categorical data variable is measured at point locations that constitute a population of interest. We then develop our new metric, the CLQ, as a point‐based association metric most similar to the cross‐k‐function and join count statistic. However, it differs from the former in that it is based on distance ranks rather than on raw distances and differs from the latter in that it is asymmetric. After introducing the statistical calculation and underlying rationale, a random labeling technique is described to test for significance. The new metric is applied to economic and ecological point data to demonstrate its broad utility. The method expands upon explanatory powers present in current point‐based colocation statistics.     

Modeling the Uncertainty of Slope and Aspect Estimates Derived from Spatial Databases

Estimates of slope and aspect are commonly made from digital elevation models (DEMs), and are subject to the uncertainty present in such models. We show that errors in slope and aspect depend on the spatial structure of DEM errors. We propose a general-purpose model of DEM errors in which a spatially auto-regressive random field is added as a disturbance term to elevations. In addition, we propose a general procedure for propagating such errors through GIS operations. In the absence of explicit information on the spatial structure of DEM errors, we demonstrate the potential utility of a worst-case analysis. A series of simulations are used to make general observations about the nature and severity of slope and aspect errors.     

Exposing Unobserved Spatial Similarity: Evidence from German School Choice Data

In a spatial context, flexible substitution patterns play an important role when modeling individual choice behavior. Issues of correlation may arise if two or more alternatives of a selected choice set share characteristics that cannot be observed by a modeler. Multivariate extreme value (MEV) models provide the possibility to relax the property of constant substitution imposed by the multinomial logit (MNL) model through its independence of irrelevant alternatives (IIA) property. Existing approaches in school network planning often do not account for substitution patterns, nor do they take free school choice into consideration. In this article, we briefly operationalize a closed‐form discrete choice model (generalized nested logit [GNL] model) from utility maximization to account for spatial correlation. Moreover, we show that very simple and restrictive models are usually not adequate in a spatial choice context. In contrast, the GNL is still computationally convenient and obtains a very flexible structure of substitution patterns among choice alternatives. Roughly speaking, this flexibility is achieved by allocating alternatives that are located close to each other into nests. A given alternative may belong to several nests. Therefore, we specify a more general discrete choice model. Furthermore, the data and the model specification for the school choice problem are presented. The analysis of free school choice in the city of Dresden, Germany, confirms the influence of most of the exogenous variables reported in the literature. The estimation results generally indicate the applicability of MEV models in a spatial context and the importance of spatial correlation in school choice modeling. Therefore, we suggest the use of more flexible and complex models than standard logit models in particular. En un contexto espacial, los patrones sustitución flexible juegan un papel importante en el modelamiento del comportamiento de las decisiones individuales. Varios problemas de correlación pueden presentarse si dos o más alternativas de elección comparten características no observables por el modelador. Los modelos de valor extremo (multivariate extreme value‐MEV) ofrecen la posibilidad de relajar la propiedad de sustitución constante (constant substitution) presente en los modelos logit multinomiales (multinomial logit‐MNL), a través de su propiedad de independencia de alternativas irrelevantes (Independence of irrelevant alternatives property ‐IIA). A menudo, los enfoques existentes en la planificación de redes escolares no toman en consideración los patrones de sustitución y de libre elección de escuela. En este artículo, los autores presentan brevemente el funcionamiento de un modelo de elección discreta (discrete choice model) para la maximización de utilidad o modelo logit anidado generalizado (generalized nested logit model‐GNL) para dar cuenta de la autocorrelación espacial. Los autores sostienen que modelos demasiado simples y restrictivos no suelen ser adecuados en un contexto de elección espacial. En contraste el modelo GNL es conveniente en términos de su computación y obtiene una estructura muy flexible de los patrones de sustitución entre las alternativas de elección. En términos generales, esta flexibilidad se logra mediante la asignación (o anidación) de las alternativas cercanas en el espacio (una alternativa puede pertenecer a varios nidos). Por lo tanto, los autores presentan un modelo de elección discreta más general. El estudio presenta además datos y la especificación del modelo para un caso de elección de escuela concreto: el análisis de libre elección de escuela en la ciudad de Dresden, Alemania. El análisis confirma la influencia de la mayoría de las variables exógenas presentes en la literatura. Los resultados de la estimación demuestran en términos generales la aplicabilidad de los modelos MEV en un contexto espacial y la importancia de la autocorrelación espacial en el modelado de elección de escuela. Los autores concluyen sugiriendo el uso de modelos más flexibles y complejos que los modelos utilizados habitualmente, en particular los modelos logit estándar. 从空间视角看,灵活的替代模式在个人行为选择建模中发挥着重要作用。当存在两个或两个以上备选方案集具有共性且无法被建模者观察到时,就可能出现相关性问题。多元极值模型（MEV）通过不相关的替代属性（IIA）实现了对多元logit模型（MNL）中常数限制的松弛替代。现有校园网络规划方法通常无法解释替代模式,而且没有考虑到自由择校因素。本文简要地建立一个封闭离散选择模型（广义嵌套（GNL）模型）,从效用最大化角度来解释空间相关性。此外分析还表明,非常简单的约束模型通常不具有足够的空间选择情境。相比之下,GNL模型计算便捷,且可以在各选择方案中获得非常灵活的替代模式。大致而言,这种灵活性大体是通过与住处位置距离上彼此靠近的替代选择分配而获得,一个给定的选择可能属于不同的住处。因此,我们给出了一个更一般的离散选择模型。此外,还给出了针对择校问题的数据和模型设定。基于德国德累斯顿市自由择校分析,证实了已有研究中多数外生变量的影响。估计结果证实了MEV模型在空间分析中的适用性以及择校模型中空间相关的重要性,并建议使用更加灵活和复杂的模型而不是标准的logit模型。     

A Fresh Look at the Egyptian Environment of the Pharaonic Period

Abstract

The article deals with the territorial history of the southern steppe areas of the Levant in the period between ca. 1050–750 BCE. In the early days of the Iron Age, until the mid-9^th century BCE, parts of them, were ruled by local desert entities: in the late Iron I a Moabite polity and in the early Iron IIA and the early years of the late Iron IIA the Tel Masos-Beer-Sheba-Negev Highlands Highlands entity. This situation changed in the later years of the Iron IIA as a result of Damascus' rise to hegemony in the Levant. In the second half of the 9^th century BCE Judah, under Damascene domination, expanded for the first time into the Beer-Sheba Valley. In the first half of the eighth century BCE, with the revival of Assyrian power in the days of Adad-nirari III, Damascene authority was replaced by north Israelite domination in the south.