The survey response rate is an important measure of the quality of a survey. Its importance depends upon whether the nonrespondents would have answered the survey questions differently. To calculate the response rate, we divide the number of organizations that responded to the survey by the number of organizations that were sampled for the survey, minus the organizations determined not to be operating at the time of the study. However, there were many organizations that we were never able to contact and thus potentially might not have been operating at the time of the survey. Therefore the response rate for this study is an estimated response rate using the final call disposition results shown in Table A3.
Final Call Disposition Results
|Final Call Disposition
|Unable to contact
|Organizations not operating at the time of the study
If we assume all the unable-to-contact organizations were not in operation, we would report a 67.1 percent response rate: (271/(615 - 211)) or 271/404 = 67.1.
If we assume all the unable-to-contact organizations were in operation at the time of the survey, we would report a 52.6 percent response rate: (271/(615 -100)) or 271/515 = 52.6.
We believe the best estimate would be to assume that the proportion of the unable-to-contact organizations that are not in operation would be the same as the proportion of organizations that were not in operation in the sample for which we were able to determine their operating status. More specifically, we were able to determine operating status for 504 organizations (that is, 615-111 = 504). Hence the overall estimated response rate for this study is 55 percent: (271/(615-100- (100/504) x 111)) = 271/493 = 55.0 .
Table A4 shows the response rate for each sampling stratum. The calculation of this rate assumes that the proportion of the unable-to-contact organizations that were not in operation would be the same as the proportion of organizations not in operation from that sampling stratum.
Response Rates by Geographic Strata
|Primary impact Mississippi
|Primary impact Louisiana
|Secondary impact Mississippi
|Secondary impact Louisiana