DEALING WITH NON-IGNORABLE NONRESPONSE BY USING AN ENTHUSIASM-TO-RESPOND VARIABLE

In the National Survey of Sexual Attitudes and Lifestyles (NATSSAL), i t is recognized that non-response is unlikely to be ignorable. In some surveys, in addition to the response variables of interest, there may also be an 'enthusiasm-to-respond' variable which is expected to be r elated to the probabilities of item and unit response. Inference techn iques to deal with non-ignorable nonresponse, based on a propensity-to -respond score, can be developed when there are both item and unit non -responders. For the NATSSAL data, an interviewer-measured interviewee embarrassment variable is combined with demographics to produce a sco re for the propensity to respond. The necessary likelihood development is outlined and alternative approaches to interval estimation are com pared. The methodology is illustrated through an estimation of virgini ty from NATSSAL data.