Randomized Response and Estimation
Trade truthful-response probability for privacy and see how it changes an unbiased prevalence estimate.
Free theory articleTrade truthful-response probability for privacy and see how it changes an unbiased prevalence estimate.
Concept & interpretation
In survey sampling, directly asking sensitive questions often leads to evasive answers or untruthful responses. The randomized response technique introduces a probabilistic privacy mechanism: a respondent answers truthfully with some probability r, and otherwise gives a random response (such as flipping a fair coin). This plausible deniability protects individual privacy while still allowing the aggregate prevalence to be estimated.
Experiment
Explore the trade-off between privacy and estimation variance:
- Set Prevalence quarters to 1.
- Set Truth quarters to 2.
- Set Respondents to 8.
- Adjust the Observed yes count and note how the Moment Estimate changes. Notice that it can exceed 1 or fall below 0, which is normal for this unbiased estimator.
- Change Truth quarters to 0 to observe that the prevalence becomes unidentifiable and the estimator unavailable.