Thirty Years of Spatial Econometrics

In this paper, I give a personal view on the development of the field of spatial econometrics during the past thirty years. I argue that it has moved from the margins to the mainstream of applied econometrics and social science methodology. I distinguish three broad phases in the development, which I refer to as preconditions, takeoff and maturity. For each of these phases I describe the main methodological focus and list major contributions. I conclude with some speculations about future directions.

From SpaceStat to CyberGIS: Twenty Years of Spatial Data Analysis Software

This essay assesses the evolution of the way in which spatial data analytical methods have been incorporated into software tools over the past two decades. It is part retrospective and prospective, going beyond a historical review to outline some ideas about important factors that drove the software development, such as methodological advances, the open source movement and the advent of the internet and cyberinfrastructure. The review highlights activities carried out by the author and his collaborators and uses SpaceStat, GeoDa, PySAL and recent spatial analytical web services developed at the ASU GeoDa Center as illustrative examples. It outlines a vision for a spatial econometrics workbench as an example of the incorporation of spatial analytical functionality in a cyberGIS.

Finite Sample Properties of Moran's I Test for Spatial Autocorrelation in Probit and Tobit Models - Empirical Evidence

In this paper, we investigate the finite sample properties of Moran’s I test statistic for spatial autocorrelation in limited dependent variable models suggested by Kelejian and Prucha (2001). We analyze the socio- economic determinants of the availability of dialysis equipment in 5,507 Brazilian municipalities in 2009 by means of a probit and tobit specifica- tion. We assess the extent to which evidence of spatial autocorrelation can be remedied by the inclusion of spatial fixed effects. We find spa- tial autocorrelation in both model specifications. For the probit model, a spatial fixed effects approach removes evidence of spatial autocorrelation. However, this is not the case for the tobit specification. We further fill a void in the theoretical literature by investigating the finite sample prop- erties of these test statistics in a series of Monte Carlo simulations, using data sets ranging from 49 to 15,625 observations. We find that the tests are unbiased and have considerable power for even medium-sized sample sizes. Under the null hypothesis of no spatial autocorrelation, their em- pirical distribution cannot be distinguished from the asymptotic normal distribution, empirically confirming the theoretical results of Kelejian and Prucha (2001), although the sample size required to achieve this result is larger in the tobit case than in the probit case.

Is the Price Right? Assessing Estimates of Cadastral Values for Bogotá, Colombia

Hedonic house price models are increasingly applied in the process of mass appraisal, in which econometric specifications are used to obtain automated valuation of properties for taxation purposes. The predictive quality of such models is important, since it directly affects the revenue stream of local authorities. In this paper, we assess the relative predictive performance of different model specifications used in automated valuation. Specifically, we focus on the issue of spatial heterogeneity by comparing models that utilize different definitions of housing submarkets. In addition, we consider the inclusion of “spatial†explanatory variables in the form of distance to various amenities as computed from a GIS. We apply this to data from the city of Bogot Ìa, Colombia, a pioneer in the application of mass appraisal techniques in a developing country context. We find that specifications that include the submarkets improve predictive performance and that the inclusion of the spatial variables is superior to the traditional models of homogenous zones. However, even the best models are still characterized by relatively poor performance in the form of a high degree of overprediction of the house value. In addition, the predictive performance of the models varied by socio-economic stratum in the city, which suggests that the dynamics of the housing markets in these strata would require closer and separate attention. These results may provide further guidance to enhance mass appraisal practice in the city of Bogot Ìa as well as potentially other Latin American cities.

Spatial Fixed Effects and Spatial Dependence

We investigate the common conjecture in applied econometric work that the inclusion of spatial fixed effects in a regression specification re- moves spatial dependence. We demonstrate analytically and by means of a series of simulation experiments how evidence of the removal of spatial autocorrelation by spatial fixed effects may be spurious when the true DGP takes the form of a spatial lag or spatial error dependence. In addition, we also show that only in the special case where the dependence is group-wise, with all observations in the same group as neighbors of each other, do spatial fixed effects correctly remove spatial correlation.spatial autocorrelation, spatial econometrics, spatial externalities, spatial fixed effects, spatial interaction, spatial weights

Advanced Trip Generation/Attraction Models

In this paper, advanced trip generation/attraction models are proposed. A multiple linear regression (MLR) model has been created from zonal data. These models are compared to each other by analyzing their hypothesis and the required adjustments. Additionally, advanced generation/attraction models considering spatial correlation are proposed, and their improvements with reference to previous models not considering spatial correlation are analyzed. A global spatial correlation model that conducts a joint review of every unit in the sample to determine whether the spatial units are randomly distributed or in accordance with a certain pattern is specified. To consider cluster situations in a given area, a local spatial correlation model aimed to measure the spatial autocorrelation to place each observation is defined. The models are applied to the Santander metropolitan area (in Spain) in order to obtain advanced generation/attraction models in that city. For Santander, the models considering spatial dependence among observations have better results than the MLR models.This work was made possible thanks to a grant from the Spanish Ministerio de Economía y Competitividad with additional financing from FEDER funds to the project TRA2012-3765

Dynamic Manipulation of Spatial Weights Using Web Services

Spatial analytical tools are mostly provided in a desktop environment, which tends to restrict user access to the tools. This project intends to exploit up-to-date web technologies to extend user accessibility to spatial analytic tools. The first step is to develop web services for widely used spatial analysis such as spatial weights manipulation and provide easy-to-use web-based user interface to the services. Users can create, transform, and convert spatial weights for their data sets on web browsers without installing any specialized software.