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2000115-Strengthening-Communities-with-Neighborhood-Data

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Advances in Analytic Methods for <strong>Neighborhood</strong> <strong>Data</strong> 379<br />

A different approach to finding clusters is based on so-called spatially<br />

constrained clustering algorithms (Duque, Anselin, and Rey 2012).<br />

This approach uses optimization methods to group spatial units <strong>with</strong><br />

similar characteristics into new regions. An application of this method<br />

to measure neighborhood change based on changing boundaries and<br />

social composition was highlighted in the MAUP discussion. The<br />

clusterPy library (GeoGrouper <strong>with</strong> a graphical user interface) and<br />

PySAL’s regionalization code implement these methods.<br />

Cluster maps can be linked to other spatial and nonspatial representations<br />

of data (such as parallel coordinate plots, scatterplots, conditional<br />

plots, histograms, or trend graphs) in open-source desktop programs<br />

such as OpenGeoDa, web platforms such as Weave (WEb-based Analysis<br />

and Visualization Environment), or through customizing visualization<br />

libraries. 11<br />

Spatial Modeling<br />

The cluster techniques discussed in the previous section are exploratory<br />

in the sense that they generally only allow for spatial pattern detection<br />

in a uni- or bivariate context or when multiple variables are considered<br />

together; this pattern detection is done visually rather than statistically.<br />

As such, these techniques are best suited for generating rather than testing<br />

hypotheses. To control for a larger number of variables in a model<br />

that tests hypotheses related to an underlying theory, multivariate spatial<br />

models are needed. If the goal is to model spatial heterogeneity (i.e.,<br />

spatial variation among regions whose similarity is not due to interaction),<br />

specialized spatial econometric methods are not needed. Discrete<br />

differences between subregions are often modeled through so-called<br />

spatial regimes <strong>with</strong> separate coefficients that can be tested for equivalence<br />

<strong>with</strong> spatial Chow tests (Anselin 1988). Further, geographically<br />

weighted regression has been popularized by Fotheringham, Brunsdon,<br />

and Charlton (2002) to estimate continuous forms of spatial variation<br />

through locally varying coefficients.<br />

However, in the context of spatial dependence, an intersection<br />

between the fields of econometrics, program evaluation, and spatial<br />

analysis continues to be missing. This lack persists despite the fact that<br />

recent research has started to strengthen the bridge between econometrics<br />

and program evaluation and the older existing connection between<br />

the fields of statistics and evaluation. 12 One of the few research projects

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