By Dan Petrella/CU-CitizenAccess — A few weeks ago, we reported on this blog that the number of same-sex unmarried couples in Champaign County increased 59 percent from 2000 to 2010, according to the U.S. Census Bureau.

It turns out, the bureau miscalculated the number of same-sex couples nationwide.

In a press release issued late last month, the bureau explained: “Statistics on same-sex couple households are derived from two questions on the census and [American Community Survey] questionnaire: relationship to householder and the sex of each person. When data were captured for these two questions on the 2010 Census door-to-door form, the wrong box may have been checked for the sex of a small percentage of opposite-sex spouses and unmarried partners. Because the population of opposite-sex married couples is large and the population of same-sex married couples in particular is small, an error of this type artificially inflates the number of same-sex married partners.”

The initial census figures showed there were 349,377 same-sex married households and 552,620 same-sex unmarried households nationwide.

Census officials were suspicious because the numbers seemed out of line with past estimates. Re-examining the data, they realized there were many names that appeared to be matched up with the incorrect sex. After reanalyzing the figures, the bureau released revised estimates. (Read more about the adjustment process on the Census Bureau’s Director’s Blog or watch the video below.)

The new, “preferred” estimates show  only 131,729 same-sex married households in the U.S., 62 percent less than the original figures suggested. 

The figures for same-sex unmarried households — the population we wrote about in our original blog post — weren’t nearly as inflated. There are 514,735 such households nationwide, according to the new esitmates, about 7 percent less than the original count indicated.

In Illinois, the original total for same-sex married households was 11,593. The adjusted estimate is 3,607, a 69 percent decrease.

The original count of same-sex unmarried households statewide was 20,876. The perferred figure is19,442, roughly 7 percent less.

Unfortunately, the Census Bureau doesn’t plan to release adjusted figures below the state level, so it’s hard to say if the figures for Champaign County were inflated or by how much.