disciplines. There are two purposes for doing this. One, population change is the primary data example used throughout this book for demonstrating the use of spatial regression models, and thus it deserves a thorough understanding on its spatial dimension to build the theoretical foundation for spatially analyzing population change. Two, many social science phenomena are studied in multiple social science disciplines with different approaches; researchers often review and adopt approaches from other disciplines. Our review of population change as a spatial phenomenon (or spatial process) can serve as a template for studying the spatial effects of other social phenomena. We then briefly introduce the state of Wisconsin to readers who are not familiar with it and follow with a description of the MCD, which is the spatial unit of analysis. Finally, we present descriptive statistics of population change in Wisconsin.
1.3.1 Population Change as a Spatial Process
Population change is considered spatially both explicitly and implicitly in existing social science literature. Population change is theorized and modeled spatially and explicitly in human geography (including population geography, geographic information sciences, transportation geography, and health geography); regional science; and environmental planning. These fields have well-established theories and methodologies for spatial data analysis of population change.
Researchers in population geography are interested in the spatial variation of population distribution, growth, composition, and migration; they seek to explain the population patterns that can be attributed to spatial regularities and processes (Bailey, 2005; Trewartha, 1953). Tobler’s (1970) first law of geography states that everything is related to everything else, but nearer things more so. Population geography’s spatial diffusion theory argues that population growth forces spread (spillover) into surrounding areas (Hudson, 1972), which implies that population growth is spatially dependent.
Researchers in regional economics explain and model changes in land use patterns, which are nearly always associated with population change (Boarnet, 1998; Cervero, 2003). For example, the growth pole theory explains, through the concepts of spread and backwash, the mutual geographic dependence of economic growth and development, which in turn leads to population change (Perroux, 1955). The central place theory puts population in a hierarchy of urban places, where the movement of populations, firms, and goods is determined by the associated costs and city sizes (Christaller, 1966). In the “new” economic geography theory, Krugman (1991) adds space to the endogenous growth and studies the process of city network formation over time.
In environmental planning, researchers study how land use changes are encouraged or discouraged by the physical environment and the socioeconomic conditions and how this, in turn, leads to population change. The approach is generally empirical, usually using GIS overlay methods to answer what-if questions. There is also similar work on developable lands (Cowen & Jensen, 1998), qualitative (Lewis, 1996) and quantitative (Cardille, Ventura, & Turner, 2001) environmental corridors, growth management factors (Land Information and Computer Graphics Facility, 2000, 2002), and a land developability index (Chi, 2010b).
Population change as a spatial process is also implicitly suggested and considered in theories of sociology (especially urban sociology, rural sociology, and sociological human ecology) and demography (especially spatial demography, rural demography, and applied demography). The spatial process of population change has already been formally incorporated into demographic models and empirical studies (Entwisle, 2007). In addition, researchers often use maps to illustrate spatial patterns and population change with multiple time frames. For a review of the large body of literature on this research, see Entwisle (2007), Fossett (2005), Logan (2012), Reibel (2007), Voss (2007), and the position paper collection Future Directions in Spatial Demography released jointly by University of California, Santa Barbara; Pennsylvania State University; and the National Institutes of Health Advanced Spatial Analysis Training Program.2
2 www.ncgia.ucsb.edu/projects/spatial-demography/docs/All-position-papers.pdf
Rural demographers study population’s spatial dimension, conducting research on population distribution and migration. They argue that migrants prefer somewhat rural or truly “sub”-urban locations within commutable distances of large cities (Brown, Fuguitt, Heaton, & Waseem, 1997; Fuguitt & Zuiches, 1975). Applied demographers often use the idea of neighbors for small-area population estimation and forecasting. For instance, they may adjust populations projected at the municipal level so that they agree with their parent county’s projections; this neighborhood context, however, is different from the spatial effects that we address in this book. Recent population forecasting research has used a modified spatio-temporal regression approach (e.g., Chi & Voss, 2011) and a geographically weighted regression approach (e.g., Chi & Wang, 2017) to formally incorporate spatial effects into the modeling.
Sociological human ecology, or the study of how human beings are affected by the environment in space and time (McKenzie, 1924), also informs sociologists of the spatial distribution of population (Berry & Kasarda, 1977; Frisbie & Kasarda, 1988). Hawley (1950) considers one of human ecology’s main topics to be spatial differentiation within urban systems, whereas Robinson (1950) views human ecology studies as using spatial information rather than individual units. And Logan and Molotch (1987) espouse that the analytical basis for urban systems in human ecology is spatial relations.
Segregation studies, one of the largest bodies of urban sociological research, likewise suggest population distribution has spatial effects (Charles, 2003; Fossett, 2005). There are several theoretical approaches explaining segregation: the spatial assimilation approach claims differences in socioeconomic statuses and associated lifestyles cause it (Galster, 1988), the place stratification approach states discrimination causes it (Alba & Logan, 1993; Massey & Denton, 1993), and the suburbanization explanation argues the suburbanization process leads to segregation (Chi & Parisi, 2011).
The spatial dimension of population dynamics is also studied by neo-Marxists, who mainly focus on population redistribution. They explain that capitalism’s pursuit of profit leads to how cities are structured, how land is used, and how population changes (Hall, 1988; Jaret, 1983). They also argue that the basis of urban development in the United States is capital accumulation (Gordon, 1978; Hill, 1977; Mollenkopf, 1975, 1981). As Hill (1977) explains, because capital accumulation occurs in an environment that is spatially structured, the geographical form and spatial patterning that it takes is (at least provisionally) urbanism.
Although there is a large body of literature on spatial demography, demography has not yet fully integrated spatial statistics and analysis methods (Hugo, Champion, & Lattes, 2003). Sociologists and demographers can benefit from the advances in spatial techniques and the availability of spatial data as these tools become more accessible and well known to develop new theories and ask new demographic and sociological questions (Chi & Zhu, 2008). Sociological and demographic perspectives of population change can be strengthened further as more researchers incorporate the spatial effects of proximity, continuity, and contagion from geography and regional science’s spatially explicit theories into new theories. For a summary of the literature, see Entwisle (2007), Fossett (2005), Reibel (2007), and Voss (2007).
It should be noted that this list of the explicit and implicit spatial theories of population change is far from complete. The implicit spatial theories come mostly from sociological and demographic perspectives, which the authors are familiar with; theories from other social science disciplines regarding population change as a spatial process are not discussed here.
1.3.2 The State of Wisconsin in the United States: The Study Area
Our
