Provides Bayesian estimation and inference for spatial autoregressive models with spatial dependence in both the response variable and the error terms. The models accommodate Gaussian, Student-t, Laplace, skew-normal, and skew-Student-t error distributions. Posterior inference is performed using Markov chain Monte Carlo methods. The package also provides posterior summaries, convergence diagnostics, residual analysis, and model comparison criteria, including the Deviance Information Criterion (DIC) and the Watanabe-Akaike Information Criterion (WAIC). See LeSage and Pace (2009, ISBN:9781420064247), "Introduction to Spatial Econometrics".