ion persons lived inside incorporated places that were not located in any metropolitan or micropolitan statistical area (outside core-based statistical areas (CBSAs)). These persons accounted for less than 5 percent of the total incorporated place population (Table 2).
Most people living in metropolitan statistical areas lived in incorporated places.
About 66 percent of the metropolitan population lived inside incorporated places (Table 1). The majority of residents in many large metropolitan statistical areas lived in incorporated places, with a few noteworthy exceptions, including the Atlanta, Baltimore, Boston,1 Philadelphia, and Washington metropolitan statistical areas,2 where most residents lived in unincorporated areas (Table 3). The largest percentages of residents living inside incorporated places tended to be found in metropolitan statistical areas in the Midwest and West regions (Figs. 1 and 2). These included the Carson City, NV Metropolitan Statistical Area, which was completely incorporated, as well as the Minneapolis, Chicago, Los Angeles, Milwaukee, Phoenix, and San Francisco metropolitan statistical areas (Table 3).
Most people living in micropolitan statistical areas lived in unincorporated areas.
About 48 percent of the population inside micropolitan statistical areas lived in incorporated places, while about 52 percent lived in unincorporated areas (Table 1). Micropolitan statistical areas with the highest percentages of residents living in incorporated places tended to be located, again, in the Midwest and West (Figs. 1 and 2). These included the Butte-Silver Bow, MT and Juneau, AK areas, which were completely incorporated. Areas with the lowest percentages tended to be located in the Northeast and South regions. Noteworthy exceptions were the Hilo, Kahului-Wailuku, and Kapaa, HI; 3 Gardnerville Ranchos and Pahrump, NV; and Los Alamos, NM micropolitan statistical areas, which were completely unincorporated (Table 3).
Table 5 shows metro areas that had at least 100 governmental units, and that also had at least 40 percent of their population in unincorporated areas. Research has suggested that these areas may be susceptible to problems associated with urban sprawl, as the number of local governments presents a challenge for comprehensive, regional land use planning efforts. This is compounded by the paucity of local land use regulations in unincorporated areas, which can exacerbate the outward expansion of urban development (Carruthers, 2003). Areas where such conditions exist vary greatly in population size, ranging from about half a million (Harrisburg, PA), to more than 5 million (Philadelphia). With the exceptions of Atlanta and Washington, these areas are mainly located in the Northeast and Midwest, where many states have multilateral annexation policies that inhibit the ability of large cities to expand their boundaries (Rusk, 2006).
The aggregate findings are generally consistent with data published in the previous study conducted by Census Bureau staff on annexation between 1990 and 2000 (Johnson et al., 2004). Metropolitan and micropolitan statistical areas with the largest percentages of their populations living inside incorporated places tended to be located in the Midwest and West regions, while areas with lower percentages tended to be located in the Northeast and South. The proportion of population living inside incorporated places in aggregate was higher in metropolitan statistical areas, lower in micropolitan statistical areas, and lowest in areas outside CBSAs. Areas typically associated with urban sprawl (e.g., Atlanta) were often found to have higher percentages of their populations living in unincorporated areas, as well as higher numbers of governmental units.
Future research needs include an examination of more recent population trends inside and outside incorporated places using the latest intercensal population estimates, as well as an analysis of the change over time of the distribution of the incorporated place population within metropolitan and micropolitan statistical areas