alpha
a scalar performing transformation on betahat and sebetahat, such that the model is $\beta_j / s_j^alpha ~ g()$,and eqnbetahat_j / s_j^alpha ~ N(0,(sebetahat^(1-alpha))^2) or student t distribution. When $alpha=0$ we have the EE model, when $alpha=1$, we have the ET model. $alpha$ should be in between 0 and 1, inclusively. Default is alpha=0.