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de Leeuw (2003); for statistical adjustment and weighting see Biemer and Christ (Chapter 16).
Item-nonresponse or item missing data refers to the failure to obtain information for one or more
questions in a survey, given that the other questions are completed. For an introduction see de
Leeuw, Hox, and Huisman (2003), for statistical approaches to deal with missing data see Chapter
18 by Rässler, Rubin, and Schenker.
Nonresponse error is a function of the response rate and the differences between respondents and
nonrespondents. If nonresponse is the result of a pure chance process, in other words if nonresponse
is completely at random, then there is no real problem. Of course, the realized sample is smaller,
resulting in larger confidence intervals around estimators
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