It occurred to me in a class session about U.S. Census data this week that it would be possible to research the number of group houses in D.C. and other places around the country. The census ask the number of members of the households and whether they constitute a family on the short form, meaning it is possible to calculate how many households have four or more unrelated roommates.

Under this definition I found in 2000 there were 2,607 group houses in the District of Columbia, just about 1% of the totally number of households in the city. The massive Washington-Baltimore consolidated metropolitan statistical area (CMSA) had 16,244 total group households, about 0.56% of the total. When all the MSAs and CMSAs are sorted by percentage of group houses, easily recognizable college towns jump to the top of the list. Here are the top ten metro areas by the percentage group houses of total households:

1. Provo, UT (4.4%)
2. State College, PA (4%)
3. Bloomington, IN (2.5%%)
4. Athens, GA (2.4%)
5. Byan-College Station, TX (2.2%)
6. Campaign-Urbana, IL (2.2%)
7. Lawrence, KS (2.1%)
8. Iowa City, IA (2%)
9. Gainesville, FL (1.9%)
10. Santa Barbara, CA (1.9%)

Sorted by the total number of group houses, the list is dominated by the largest MSAs:

1. New York-Northern New Jersey-Long Island
2. Los Angeles-Orange County
3. San Francisco-Oakland-San Jose
4. Washington-Baltimore
5. Boston
6. Chicago-Gary-Kenosha
7. Atlanta
8. Philadelphia-Wilmington-Atlantic City
9. Seattle-Tacoma
10. Dallas-Fort Worth
(And I can’t exclude #11 – Detroit-Ann Arbor-Flint)

Of course, a more detailed analysis is possible as some of these CMSAs are quite large.