Optimization of the Unrelated Question Randomized Response Model

In their article [1] B. G. Greenberg, et al. discussed Simmons' modification of Warner's Randomized Response Technique and advised on the choice of the parameters in the model. One of their recommendations, however, is far from being the most efficient. The correctness of their other recommendations is proved and it is shown that the optimized method is superior to Warner's Technique.