Missing Data and Response Rates

I'm getting ready to teach a seminar on the calculation of response rates. Although I don't work on telephone surveys much anymore (and maybe fewer and fewer other people do), I am still intrigued by the problem of calculating response rates in RDD surveys.

The estimation of "e" is a nice example of a problem where we can say with near certainty that the cases with unknown eligibility are not missing at random. This should be a nice little problem for folks working with methods for nonignorable nonresponse. How should we estimate "e" when we know that the cases for which eligibility is unobserved are systematically different from those for which it is observed? The only thing that could make this a more attractive toy problem would be if we knew the truth for each case.

Probably this problem seems less important than it did a few years ago. But we still need estimates of "e" for other kinds of surveys (even if they play a less important role in other surveys).

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