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. Author manuscript; available in PMC: 2020 Mar 1.
Published in final edited form as: Risk Anal. 2018 Oct 25;39(3):616–629. doi: 10.1111/risa.13218

Table 1.

Summary statistics and recommended empirical prior distributions for Models (1)–(8) developed from QRAD. Model numbers and parameters correspond to those described in the text. For recommended priors: N(μ,σ2) indicates a normal distribution with mean μ and variance σ2, LN(μ,σ2) indicates a log-normal distribution with mean exp{μ + ½σ2} and variance (exp{σ2}  1)exp{2μ + σ2}, while Beta(a,b) indicates a Beta distribution with shape parameters a and b.

sample statistics
Model parameter minimum median maximum mean variance recommended prior
Quantal linear (1) γ 0 0.041 1 0.109 0.025 γ~ Beta(0.313, 2.545)
β1 0 0.583 17.770 −0.470* 1.688* β1 ~ LN(-0.470, 1.688)
Multi-stage (2) γ 0 0.041 0.947 0.112 0.025 γ~ Beta(0.326, 2.582)
β1 0 0.241 11.394 −1.006* 4.949* β1 ~ LN(-1.006, 4.949)
β2 0 0.063 15.874 −1.016* 5.013* β2 ~ LN(-1.016, 5.013)
Weibull (3) γ 0 0.034 0.947 0.095 0.022 γ~ Beta(0.271, 2.583)
α 0.20 1.051 17.619 −0.243* 2.467* α-0.2 ~ LN(-0.243, 2.467)
β 0 0.706 11.388 −0.464* 1.535* β ~ LN(-0.464, 1.535)
Gamma (4) γ 0 0.034 1 0.097 0.023 γ~ Beta(0.276, 2.572)
α 0.20 1.098 17.799 −0.153* 2.637* α-0.2 ~ LN(-0.153, 2.637)
β 0 0.924 16.119 −0.587* 5.659* β ~ LN(-0.587, 5.659)
Logistic (5) β0 −16.491 −2.446 2.889 −2.526 3.733 β0 ~ N(-2.526, 3.733)
β1 0 2.734 16.734 1.018* 0.603* β1 ~ LN(1.018, 0.603)
Log-Logistic (6) γ 0 0.031 1 0.097 0.023 γ~ Beta(0.275, 2.571)
β0 −4.789 0.095 7.353 0.203 4.061 β0 ~ N(0.203, 4.061)
β1 0.200 1.314 17.760 0.274* 0.960* β1 ~ LN(0.274, 0.960)
Probit (7) β0 −11.844 −1.431 1.619 −1.660 3.264 β0 ~ N(-1.66, 3.264)
β1 0 1.537 13.519 0.473* 0.638* β1 ~ LN(0.473, 0.638)
Log-Probit (8) γ 0 0.050 0.947 0.104 0.022 γ~ Beta(0.333, 2.877)
β0 −17.400 0.047 11.176 −0.514 10.337 β0 ~ N(-0.514,10.337)
β1 0.200 0.914 5.926 −0.186* 0.579* β1 ~ LN(-0.186, 0.579)
*

Reported mean and variance based on sample values after logarithmic transformation; values for α component in Models (3) and (4) are based on log(α′) = log(α – 0.2).