ANALYSIS OF A DYNAMIC RESIDENTIAL LOCATION CHOICE MODEL WITH TRANSACTION COSTS*

ABSTRACT. This paper incorporates transaction costs in a residential location choice model. An individual's choice is assumed to be an outcome of a two-stage process: a decision to change, or to undertake a transaction and, conditional on a change occurring, a choice of a new alternative. The dynamic choice model is aggregated to yield a Markovian model of residential location patterns. It is shown that recent contributions to dynamical urban modeling correspond to special cases of the deterministic version of this model. The Markovian model is used in a theoretical analysis of the influence of transaction costs on the properties of the stationary state. The effects of residential mobility rates and of interdependencies among individuals, caused by supply-side and density-related interactions, are also analyzed. It is shown how these dynamical factors modify the stationary state, thereby demonstrating the type of errors which may occur with static models that omit them.     

A GENERAL FRAMEWORK FOR THE INTEGRATION OF A LAND-USE MODEL WITH A TRANSPORTATION MODEL COMPONENT

Integrated land-use—transportation models are characterized as models in which the redistributive effects of one subsystem upon the other are explicitly defined and incorporated into the model's structure. At the core of integrated models is a linking procedure whose function is to transform the outputs of one model component into inputs for the other. Despite major efforts made in the past to build operational large scale integrated models, the structural properties of such models remain largely unexplored. This paper describes a general framework for an integrated model consisting of prototype model components. These are an iterative activity allocation model of the Garin-Lowry type, an equilibrium-assignment transportation network model, and a linking procedure. Given the level of analysis, this framework is shown useful for exploring the analytics of integrated models and, in particular, their equilibrium properties. By means of many simulation experiments based on an hypothetical numerical example, the operation of the model is demonstrated with an emphasis on the locational interpretation of the integration procedure. On the basis of the empirical results and considering the model's intrinsic assumptions, the following major findings can be cited. First, the effects of nontravel factors (such as basic employment and zonal attractions) upon activity distribution are stronger than effects caused by changes in the transportation system. The latter effects were found to yield nonlinear and, spatially, nonuniform changes in activity location which also tended to be larger in peripheral regions. Second, implicit in the specification of the integration procedure are behavioral assumptions regarding time-lags in locational adjustments made by activities in reaction to rising cost of travel. The present formulation implies that once located, activities do not revise their locational decisions despite substantial increases in travel costs. At the other extreme, all activities are permitted to readjust their locational preferences after the final interzonal travel costs are derived. The effect upon activity distribution of the latter specification is, of course, larger than that of the former, although less than the effect yielded by changes in nontravel factors. Regarding the equilibrium properties of the integrated system, both the theoretical and empirical analyses show that the entire model will converge into an equilibrium solution and that the corresponding trip patterns are also at equilibrium. These results will hold as long as the operation of the integrated models is completely controlled by the generation functions of the land-use model and the transportation model component only affects the spatial distribution of activities. Finally, the results from the simulation experiments indicate that the computed mean travel cost parameter tends to stabilize around a certain value as the level of demand for travel, within the system, rises. There is evidence that compensating changes in the location and composition of this demand are the main causes of this phenomenon. In light of these findings, it is possible to point to three key problems whose resolution could largely improve the predictive power of integrated models. First, it would be useful to define activity models in which the generation of activities is, among other things, a function of travel conditions. Second, currently formulated integrated models do not contain trip demand functions and, thus, demand for travel by an activity unit is regarded as completely inelastic. Third, different locating activities respond differently—over time and space—to changíng travel conditions, and models should, therefore, reflect explicitly such differences in activity behavior. A recent paper by Los [14], is an important contribution to the analysis of this issue.     

A DAMAGE MODEL FOR THE ANALYSIS OF THE SEISMIC RESPONSE OF MONUMENTAL BUILDINGS

In this paper the Author proposes a damage model for the analysis of masonry plates and shells, which is based on an improvement of a previous constitutive model. The modifications introduced, connected to the head joint damage, allow us to study the influence of masonry texture on the damage modes once the mechanical characteristics of the elements constituting the masonry and the results of tests on simple assemblages are known. Having a nonlinear constitutive model is certainly one of the basic elements for understanding the damage mechanisms in masonry buildings. If, in fact, an elastic-linear constitutive model may be used under normal loading conditions, in critical situations it is necessary to model the damage and the dissipation mechanisms that occur between the elements, stone (brick) and mortar, in correlation with their characteristics and kind of masonry. To validate the model a comparison is made between the numerical and experimental results, in the case of tests available in the literature in masonry panels subjected to out-of plane loading and in a real structure through the observation of the damage in Umbria (Italy) surveyed after the 1997 earthquake.     

CRIME IN A MULTI‐JURISDICTIONAL MODEL WITH PRIVATE AND PUBLIC PREVENTION*

ABSTRACT Criminals move between jurisdictions in response to differences in the net returns to crime that depend on the opportunity for crime and the effort to prevent crime. An increase in police protection of a jurisdiction diverts crime to other jurisdictions when only public crime prevention such as police protection is available. However, residents also invest in private prevention (private security, burglar alarms, etc.), and the value of these measures depends on the level of local public protection. In a spatial context, an increase in public prevention of a jurisdiction not only alters the incentives of individuals of the jurisdiction, but also of other jurisdictions as well, and such a change in private crime prevention may end up attracting crime to the jurisdiction. An increase in public prevention of a jurisdiction thus may divert or attract crime. This ambiguous effect stands in contrast with the literature and may appear counterintuitive, but is logical under plausible conditions.     

A SPATIAL CLIFF‐ORD‐TYPE MODEL WITH HETEROSKEDASTIC INNOVATIONS: SMALL AND LARGE SAMPLE RESULTS*

ABSTRACT In this paper, we specify a linear Cliff‐and‐Ord‐type spatial model. The model allows for spatial lags in the dependent variable, the exogenous variables, and disturbances. The innovations in the disturbance process are assumed to be heteroskedastic with an unknown form. We formulate multistep GMM/IV‐type estimation procedures for the parameters of the model. We also give the limiting distributions for our suggested estimators and consistent estimators for their asymptotic variance‐covariance matrices. We conduct a Monte Carlo study to show that the derived large‐sample distribution provides a good approximation to the actual small‐sample distribution of our estimators.     

POPULATION DISPERSION VS. CONCENTRATION IN A TWO‐REGION MIGRATION MODEL WITH ENDOGENOUS NATURAL AMENITIES*

ABSTRACT Contrary to the predictions of the basic spatial equilibrium model, the long‐run distribution of population across rural U.S. counties with high‐valued natural amenities has become relatively more concentrated versus dispersed. We provide an explanation by developing a two‐region model with mobile labor, production externalities and endogenous natural amenities. We find that strong preferences for natural amenities generally foster population dispersion. However, such preferences can also lead to population concentration when ecological degradation is low and man‐made capital is a relatively scarce input into natural amenity production. Investments that enhance natural amenities are found to reduce the divergence between the steady state and optimal outcomes.     

A DYNAMIC INTRSECTORAL,MODEL OF REGIONAL ECONOMIC GROWTH*

ABSTRACT. The dynamic relationship between sectoral value added and regional economic growth is analyzed using a stochastic intersectoral model estimated by ordinary least squares and linear systems techniques. A state-space portion of the model identifies the time element of sedoral value added. Dynamic multipliers, tracing the temporal path of regional growth, are calculated for the state of Georgia over the period 1963–1986. This application shows that the impacts of sectoral shocks can follow cyclical as well as monotonic patterns and that the direction and magnitude of the impact may change over time.     

LOCATION AND ENTREPRENEURSHIP: INSIGHTS FROM A SPATIALLY‐EXPLICIT OCCUPATIONAL CHOICE MODEL WITH AN APPLICATION TO CHILE

Occupational choice and heterogeneous managerial ability enter a spatial Dixit‐Stiglitz setting, linking location, wages and regional entrepreneurship rates. Market potential has a positive partial effect and wages a negative partial effect on the regional supply of entrepreneurs, both balancing in equilibrium with endogenous wages. Market potential increases profits, but also the opportunity cost of entrepreneurship. In the long‐run equilibrium with perfect mobility, the cut‐off level of ability determining selection into entrepreneurship will be the same across regions; moreover, regional differences in entrepreneurship rates depend only in differences in average fixed costs of firms. An empirical application is provided for Chile.     

EVIDENCE OF POLITICAL YARDSTICK COMPETITION IN FRANCE USING A TWO‐REGIME SPATIAL DURBIN MODEL WITH FIXED EFFECTS*

ABSTRACT This research proposes a two‐regime spatial Durbin model with spatial and time‐period fixed effects to test for political yardstick competition and exclude any other explanation that might produce spatial interaction effects among the dependent variable, the independent variables, or the error term. The study also derives the maximum likelihood estimator and variance–covariance matrix of the parameters of this model. Data pertaining to welfare spending by 93 departments in France during 1992–2000 provide significant empirical evidence in support of political yardstick competition. Departments governed by a small political majority mimic neighboring expenditures on welfare to a greater extent than do departments governed by a large political majority.     

INVESTIGATING MATERIAL DECAY OF HISTORIC BUILDINGS USING VISUAL ANALYTICS WITH MULTI‐TEMPORAL INFRARED THERMOGRAPHIC DATA

This paper shows how visual analytics methodology can be used to facilitate interpretation of multi‐temporal thermographic imagery for the purpose of restoration of cultural heritage. We explore thermographic data in a visual environment from the unifying spatio‐temporal perspective in an attempt to identify spatial and spatio‐temporal patterns that could provide information about the structure and the level of decay of the material, and the presence of other physical phenomena in the wall. The approach is tested on a thermographic dataset captured on the façade of a Romanesque building from the 13th century—the Cathedral in Matera (Italy).     

A MICROMECHANICAL INELASTIC MODEL FOR HISTORICAL MASONRY

A micromechanical damage model for the Snite element modelling of historical masonry structures is presented in this article. Masonry is considered as a composite medium made up of a periodic assembly of blocks connected by orthogonal bed and head mortar joints. The constitutive equations, in plane stress, are based on the homogenisation theory and they consider the non linear stress-strain relationship in terms of mean stress and mean strain. Different in-plane damage mechanisms, involving both mortar and blocks, are considered and the damage process is governed by evolution laws based on an energetic approach derived from Fracture Mechanics and on a non-associated Coulomb friction law. The failure domain of the model is analysed both in the equivalent stress and in the principal stress space considering different orientations of the bed joints relative to the loading direction. A comparison with experimental results is provided. A numerical simulation of masonry walls subjected to horizontal forces proportional to their own weight is shown in order to discuss the model's capability of describing the influence of the masonry microstructure on its mechanical behaviour.     

TIEBOUT DYNAMICS: NEIGHBORHOOD RESPONSE TO A CENTRAL‐CITY/SUBURBAN HOUSE‐PRICE DIFFERENTIAL*

ABSTRACT We take advantage of an unusual natural experiment—a high‐quality 1920s subdivision split neatly in half by a central‐city/suburban boundary—to study the response over 30 years to the relative decline in the quality of central‐city services since the 1960s. As expected, a large sale price differential opens in the 1960s. Demographic characteristics are nevertheless similar across the boundary. Survey data indicate Tiebout sorting: the central city side attracts households who prefer alternatives to suburban public schools. Children attend parochial and public “magnet” schools. A neighborhood association supplements municipal services. Rigid service district boundaries inhibit closure of the house‐price differential.     

MEAN SHIFT: A NON‐PARAMETRIC ALGORITHM FOR THE SEGMENTATION OF ANOMALIES IN GEOPHYSICAL IMAGES OBTAINED FROM MAGNETIC PROSPECTION DATA

This paper studies the applicability of the Mean Shift algorithm as support in interpreting geophysical images produced, on this occasion, from magnetic prospection data. The data obtained from a magnetic survey carried out in Gilena (Seville province, Spain) by the La Rábida Archaeophysics Group will be used for the research. Its applicability is illustrated by comparing, on the one hand, some reduction‐to‐pole algorithms and on the other, the (well‐known) k‐means algorithm. Finally, the paper shows the results obtained by applying the Mean Shift algorithm as an alternative method to ‘unsupervised clustering’ of anomalies that appear in images obtained from geophysical data, in which the a priori knowledge of the number of classes is difficult or impossible.     

HOUSING CONSUMPTION DECLINES WITH INCOME IN THE OPEN‐CITY MODEL: THEORY AND EMPIRICAL EVIDENCE

This paper demonstrates that the standard urban model (SUM) has important, previously unknown, and rather counterintuitive predictions about the determinants of housing consumption in cities. For example, the SUM predicts that, as higher wages in the central business district prompt city growth, the housing space per household falls, that is, rising income is associated with falling housing consumption. Empirical testing using a specially constructed panel data set of U.S. cities, confirms this prediction. When city size, income, and housing price rise, housing space per household falls.