In previous posts on this topic, I have argued that the term "exurban" has been used in a scandalously confused way, categorizing so much of suburbia as exurban that the term loses any meaning. In particular, I took a close look at the definition of exurbia used by the National Committee for an Effective Congress (NCEC), a leading Democratic targeting firm. Here is some of what I reported:

[NCEC's original criteria] indicate that pretty much any suburban county that does not contain a large city can be designated as exurban, if it is relatively downscale in terms of occupation, income and education or if it falls below a certain density criterion. [Note: these original criteria also appear to categorize any non-rural county with a minority population over 50 percent as an urban county.]....

1. Some entire MSAs (metropolitan statistical areas) are designated exurban, like the Canton MSA in Ohio and the Pensacola and Sarasota MSAs in Florida.

2. In other MSAs, only the county containing the MSA's main city is designated "urban-surburban" while every other county is designated exurban or even rural. For example, in the Columbus, OH MSA, only Franklin county is termed urban-suburban, while five other counties are designated exurban and two are considered rural. Similarly, all Ohio counties in the Cincinnati MSA are designated exurban except Hamilton county.

3. Medium-sized metro areas wind up being classified almost entirely as exurban or rural. In Florida, for example, there are 16 counties in medium-sized metro areas. Of these, just three are classified as either urban-suburban (1) or suburban (2), while 13 are classified as either exurban (11) or rural (2).

4. Almost no counties are simply designated "suburban". In Ohio, there are only three (compared to 30 exurban counties); in Florida, just five (compared to 21 exurban counties)....

Collapsing all but the most urbanized parts of big metro areas, almost the entirety of medium-sized metro areas and outer suburbs everywhere into exurbia does considerable violence to the concept and clarifies little.

Arguably, what the NCEC criteria are really doing is categorizing all suburban counties where downscale white voters predominate as "exurban". Not surprisingly, given recent voting trends among white working class voters, these suburban counties tend to vote Republican. But calling these counties exurban simply confuses the issue: why not call them Republican-Leaning Suburban Counties (RLSCs) instead? That would be clearer and more analytically justified (though less trendy).

I have now obtained a categorization of every county in the US on the basis of NCEC's original criteria and have conducted some analysis using their categories. (Note: they appear to have modified their criteria slightly since their original criteria were elaborated, but I do not have access to these modified criteria.) This analysis produces some interesting results which further underscore, I think, the need for much more careful and selective use of the term "exurban".

1. By NCEC's definition, 581 counties in the US are exurban and just 131 are suburban.

2. By NCEC's definition, 29 percent of the US poplation lives in exurbia and just 19 percent in suburbia (!). (If you've got a geographer friend, tell that one to him/her to get a good laugh.)

3. NCEC's exurban counties provided 31 percent of the vote in 2004, 2 points over their population share of 29 percent. Note that these counties provided 30 percent of the vote in both 2000 and 1996, so the exurban share of the vote, even under NCEC's peculiar definition, is increasing very slowly, not rapidly.

4. Once you adjust the increase in votes in these counties for population increase (see my earlier post on this subject), their adjusted rise in turnout in 2004 was actually less than in rural, suburban and urban counties, as defined by NCEC.

5. Republican domination of these counties is, as I argued previously, nothing new. Even under NCEC's definition, Reagan carried exurban counties by 27 points in 1984, compared to just 15 points for Bush in 2004. In fact, Bush's papa in 1988 actually did better than his son in these counties, carrying them by 17 points. The only area where Bush bested his papa was in rural counties (by NCEC's definition), carrying them by 19 points, compared to 11 points for his father (though Reagan carried them by 24 points). And Bush did way worse than his father in NCEC's suburban counties, losing them by 5 points, while his father carried them by 11 in 1988 (and Reagan carried them by 21 in '84); he also did much worse in NCEC's urban counties, losing them by 19 points, while his father lost them by only 5 points in '88 (and Reagan actually carried them by 4 points in '84). All this underscores the "Reagan lite" nature of Bush's coalition.

Bottom line: we're still looking for a definition of exurbia that clarifies more than confuses and adds real analytical value. I am in touch with some geographers who are trying to come up with a clear, tight definition rooted in standard practices in their field. I'll report back when their efforts have (hopefully) borne some fruit.