We all believe that telephone response rates have declined sharply over the last decade but documenting that decline with real numbers has been a bit elusive. For a number of years CMOR did a cooperation rate study but, to be blunt, it was poorly designed and not all that useful beyond the general conclusion that things kept getting worse.
Now along comes a study by Curtin, Presser, and Singer (POQ, 2005, vol 69, no. 1) that looks at changes in the response rate to UM’s long-running Survey of Consumer Attitudes. Their research updates an earlier study of the period from 1979 to 1996 and also looks at the more recent period from 1997 to 2003. Their results show that the decline was steeper than the original study had shown and that things have gotten worse since. To wit:
- Between 1979 and 1996 the response rate fell from a high of 72% to a low of 60% (about .75% per year).
- Since 1996 the response rate has fallen at about twice that rate (about 1.5% per year) down to a 2003 response rate of 48%.
- The main cause of nonresponse in the earlier period was refusals, with noncontacts only a small percentage. Since 1996, noncontacts have emerged as the principal source of nonresponse. In other words, people have stopped answering their phones.
- Even with the introduction of some tried and true response improvement techniques (advance letters and $5.00 incentive) over the last few years they have been unable to improve the response rate.
Bear in mind that this is a pretty rigorous phone study. The number of dial attempts has been mostly limited only by the field period. They were calling up to 12 times before treating a number as non-working but that has been reduced to six calls. They try to convert every initial refusal and, as noted above, use classic response improvement techniques.
Now to put this in the context of what we do at MSI. For starters, most of our work uses a much less rigorous design for two reasons: (1) it costs more than most commercial clients want to pay and (2) most of our clients place greater value on getting data sooner as opposed to waiting to get a higher response rate. We use more rigorous designs for academic work and have in the past reached the kind of response rates that are reported above. Probably the most recent examples was the 2000 National Election Study where with considerable effort we got close to 55%.
All in all, it just keeps getting tougher.