RE: AHS Do You Need Degree Days?

From: American Housing Survey (AHS) ListServ <ahs@huduser.gov>

My thanks to everyone who replied to my question about heating and cooling degree days. It's always interesting to see what will or will not trigger a discussion on an electronic forum.

I'd like to clarify a few points regarding degree days and the American Housing Survey. AHS has nothing to do with defining degree days for any location. The survey is a user of such data, not a producer. We obtain the average heating and cooling degree days for the counties in which we have sample cases and append the data to the AHS public use file as a six-category code, in the variable DEGREE. The purpose of this code is to allow AHS users some information about the local climate of each housing unit. This information can be useful when studying such things as utility costs, energy use, demand for heating and cooling equipment, attractiveness of the location, and so on.

If AHS drops DEGREE from its public use files in 2015, heating and cooling degree day data will still be available from the sources of such data, such as the National Oceanic and Atmospheric Administration (NOAA).

I appreciate all those who replied explaining how they used DEGREE in their work with AHS data. That was exactly what I was trying to discover. We will have to think again about how (and if) we can accommodate such uses while still being able to identify the geography of Census Divisions and states that we hope to incorporate into the 2015 and later datasets. One possibility would be to simply report DEGREE values at the level of the smallest geography that we include. Thus we would use state or divisional averages rather than county. We might also report DEGREE as a continuous variable rather than a six-level categorical variable. However, that might make the disclosure problem even worse; that's one matter I will need to discuss with the Census Bureau. Finally, some have mentioned that the Residential Energy Consumption Survey (RECS) also includes degree days in their files. We will check with RECS to see what other geography they report and how they handle the disclosure problems.

Thank you all for your comments. We will go back to work and see if we can find a way to accommodate your needs while still expanding the geographic detail in the AHS.

Dav Vandenbroucke
Senior Economist
U.S. Dept. HUD
david.a.vandenbroucke@hud.gov
202-402-5890

I disclaim any disclaimers.