Automatic Bayesian model averaging for linear regression and applications in Bayesian curve fitting

With the development of MCMC methods, Bayesian methods play a more and more important role in model selection and statistical prediction. However, the sensitivity of the methods to prior distributions has caused much difficulty to users. In the context of multiple linear regression, we propose an automatic prior setting, in which there is no parameter to be specified by users. Under the prior setting, we show that sampling from the posterior distribution is approximately equivalent to sampling from a Boltzmann distribution defined on C-p values. The numerical results show that the Bayesian model averaging procedure resulted from the automatic prior settin provides a significant improvement in predictive performance over other two procedures proposed in the literature. The procedure is extended to the problem of Bayesian curve fitting with regression splines. Evolutionary Monte Carlo is used to sample from the posterior distributions.