I’ve read a couple of articles expressing shock at the level of vacant housing units in the redistricting files from the 2010 Census. I’ve also read a blog from one user who thought the totals for vacant units from our Housing Vacancy Survey compared to the 2010 Census were too high for the four states released thus far. To avoid misinterpretation of what these the counts mean, we should make clear a number of points.

We delivered counts of total housing units and counts of vacant housing units. However, the total vacant count includes units intended for rent or for sale, units intended for seasonal, recreational or occasional use, units for migratory workers (a very small number), and other vacant units that did not fit into these categories (usually held off the market for personal reasons of the owner). Seasonal, recreational, or occasional vacant houses were prevalent in April, 2010, especially in resort areas where there are cottages, condominia, and homes that are used only during the given tourist season.

Using the delivered total vacancy counts that include seasonal, recreational or occasional use vacant units can mislead a user who wants to measure the impact of the housing crisis in such an area. On the other hand, a large number of this type of vacant units in areas where you would expect higher occupancy rates at the time of the census or areas where there may have been high expectations of second home purchases may also indicate a housing problem. Later reports from the 2010 Census will show the vacancy status for all vacant housing units and will also show whether occupied units were owned or rented.

I would also note that we collect data on vacant units from several other surveys, and you will find that there will be differences, sometimes noticeable differences, between the results provided by the 2010 Census and those from these other surveys. There are number of reasons why these numbers may differ. For example, we attempt to measure the occupancy status of units on April 1, 2010 – a single day. Most surveys that supply vacancy rates measure the status of sample units at the time the field representative conducts the interview. Census enumerators returned to units thought to be vacant over several months to verify the status, but always attempted to measure status as of April 1, 2010. We will be actively investigating these differences as we evaluate the 2010 Census results.