Sample surveys with sensitive questions: A nonrandomized response approach

Since the Warners randomized response (RR) model to solicit sensitive information was proposed in 1965, it has been used and extended in a broad range of surveys involving sensitive questions. However, it is limited, for example, by a lack of reproducibility and trust from the interviewees as well as higher cost due to the use of randomizing devices. Recent developments of the alternative non-randomized response (NRR) approach have shown the promise to alleviate or eliminate such limitations. However, the efficiency and feasibility of the NRR models have not been adequately studied. This article introduces briefly the NRR approach, proposes several new NRR models, compares the efficiency of the NRR and RR models and studies the feasibility of the NRR models. In addition, we propose the concept of the degree of privacy protection between the NRR model and the Warner model to reflect the extent the privacy is protected. These studies show that not only the NRR approach is free of the limitations of the randomized approach but also the NRR model actually increases the relative efficiency and the degree of privacy protection. Thus, the non-randomized response approach offers an attractive alternative to the randomized response ap.