Response to Lubin's proposed explanations of our discrepancy.

Lubin's proposal that a correlation between radon and smoking among individuals might explain the very large discrepancy between our data on U.S. counties and the prediction of linear no-threshold theory of radiation induced cancer is tested. It is shown that even correlations far beyond the limits of plausibility cannot explain an appreciable part of our discrepancy. On the other hand, Lubin is commended for proposing a definite potential explanation for our discrepancy that can be quantitatively tested for applicability to our analysis, and further such proposals are strongly invited. All other explanations of our discrepancy and all other reasons for not accepting our conclusions that are proposed in the Lubin paper are shown not to be applicable. The role of plausibility in epidemiological studies is discussed and shown to be all-important.