In urban planning circles, Portland, Oregon is held up as a model of urban planning. It is designed to be highly walkable, has an extensive system of bike routes, good public transportation, and was one of the first cities in the country to make sustainability a priority. As is often the case, being held up as a model by one group invites criticism by another and a recent post at the iconoclastic planning website newgeography.com takes Portland to task for lacking diversity and being all-white.
It is true that Portland is not a very diverse city and, if author Aaron Renn had left his criticism at Portland, he would have had a much stronger argument, but he does not. Instead, he argues that "the best, the most progressive and best role models for small and mid-sized cities" are havens of white exclusivity and goes on to present an array of statistics to demonstrate this point. In his analysis, there are flaws in the way that he presents the data. In particular, despite his claim that these progressive models are "White Cities," he doesn't actually present the percentage white in cities. In fact, he doesn't present data for cities at all — he presents statistics for "Core Counties" (these are counties that contain the central city).
Renn addressed the second of the two criticisms in the comments of his post by saying:
Comparisons between cities are inherently difficult. I generally do not like to use central city corporate limit data as a basis for comparison because the size of central cities is so different. Indianapolis and Columbus are both large because they annexed large amounts of "suburban" territory, while Cincinnati and Cleveland did not and are much smaller geographically.
I agree that it is difficult to compare different cities because cities vary both geographically and administratively. But, the same could be said about cities and, given that Renn is discussing "progressive" policies, then it seems like corporate limits would be exactly what he would want to report because in almost all areas in the country (Indianapolis being a major exception) policies are decided within municipal boundaries. In fact, the political fragmentation is associated with racial isolation/segregation. Furthermore, there is no reason to believe that counties vary widely in their administration and autonomy.
Perhaps more problematically, while Renn makes the argument that model progressive cities are white havens, he does not present any statistics on how white cities are. Instead, he publishes the percentage black in the core county. This brings up two problems. First, it assumes that the American population is made up of only whites and blacks and ignores the increasing racial diversity in many cities including the mass immigration by Latinos and Asians. Second, this also assumes that the mere presence of blacks means that cities are diverse; however, if there are lots of African Americans, but they are segregated into a small number of specific neighborhoods (e.g., Detroit, Cleveland, Gary, Milwaukee) then these cities cannot be said to be diverse.
In order to look at what impact these assumptions have on the conclusions that Renn draws, I have taken Renn's examples of model progressive cities: Portland, Austin, Denver, Minneapolis, and Seattle and charted the percentage of residents by racial composition in each central city. The chart gives a much different impression than that given by Renn's charts. Using central cities and charting racial composition by multiple groups shows that both Austin and Denver have only 50% of whites in their municipal limits while Minneapolis is only 63% white. Seattle is slightly higher than Minneapolis with 68% white while Portland — Renn's poster child — is 74% white. In the United States in 2000, only 75% of the population was white meaning that Portland would be right on the average of the entire nation if the entire U.S. population were spread out without clustering. Although the percentage of white residents in Portland is certainly higher than most cities, the fact that one in four residents in the city means that the city cannot be identified as only white as Renn implies.
But, even if a city had a large non-white population, it does not mean that residents are integrated or interact with one another. I downloaded the metropolitan area segregation statistics from the to see how racially segregated these metropolitan areas are. I use three measures available for download from The Mumford Center. Although there are multiple domains of segregation that can be measured, I focus on two here: the dissimilarity index and the white isolation index. The first measures the extent to which residents of two different races are evenly distributed in neighborhoods (i.e., tracts) within a metropolitan area and the second measures the neighborhood percent white of the average white resident. The former is unaffected by the relative size of the two groups being compared, while the isolation index is dependent on both the size of the white population and its geographic dispersion (a greater percent white in a metro area pushes isolation higher).
Generally, scores on either indices above 60 are considered extreme segregation. Denver is the only city above this threshold for black/white dissimilarity, though Minneapolis is close at 57.8. Dissimilarity in the other cities, while high (30 is generally considered high) are not terribly segregated. Latino/white dissimilarity scores were much lower, though Denver again stood out for being among the highest. All of these cities have extreme levels of isolation but, again, Portland is an extreme outlier — probably owing to its disporportionately white share of the population relative to the other cities. Just for comparison's sake, I also queried the segregation indices for the largely Midwestern cities Renn held up as examples of diversity. Those indices are presented below. The comparison is shocking: with the exception of Nashville, all of the cities have higher levels — often much higher levels — of black/white segregation. Latino/white segregation is comparable to those of the "model progressive" cities (with the exception of very low levels in Cincinatti). And, perhaps more tellingly, the isolation index scores for Renn's alternative Midwestern cities are much higher than three of the "model progressive" cities (Austin, Denver, and Seattle), though Portland still retains the highest white isolation score of any of the metropolitan areas.
Thus, while Renn certainly has a case about Portland being held up as a model for progressives despite its lack of diversity, the data simply doesn't back up his arguments for the remaining cities he identifies as models of progressive communities. Even worse, cities he holds up as alternatives because of their diversity tend to be more segregated than the progressive cities that he flogs in his post. While he brings up important points to consider in discussing urban planning and policies — considering the importance of diversity in comparison to "livable" environments — unfortunately, he gives the wrong impression of most of the cities and draws the wrong, sometimes drastically wrong, conclusion about the relative levels of diversity in these cities.
 I know that I am switching geographic units here, but metropolitan areas gives a better impression of what effect differences in urban versus suburban racial composition would have on racial segregation