Template-Type: ReDIF-Paper 1.0 Author-Name: Bauwens, L. Author-Name-Last: Bauwens Author-Name-First: Luc Author-Person: pba4 Author-Name: Bos, C.S. Author-Name-Last: Bos Author-Name-First: Charles Author-Person: pbo94 Author-Name: van Dijk, H.K. Author-Name-Last: van Dijk Author-Name-First: Herman Author-Person: pva325 Author-Name: van Oest, R.D. Author-Name-Last: van Oest Author-Name-First: Rutger Title: Adaptive polar sampling, a class of flexibel and robust Monte Carlo integration methods Abstract: Adaptive Polar Sampling (APS) algorithms are proposed for Bayesian analysis of models with nonelliptical, possibly, multimodal posterior distributions. A location-scale transformation and a transformation to polar coordinates are used. After the transformation to polar coordinates, a Metropolis-Hastings method or, alternatively, an importance sampling method is applied to sample directions and, conditionally on these, distances are generated by inverting the cumulative distribution function. A sequential procedure is applied to update the initial location and scaling matrix in order to sample directions in an efficient way. Tested on a set of canonical mixture models that feature multimodality, strong correlation, and skewness, the APS algorithms compare favourably with the standard Metropolis-Hastings and importance samplers in terms of flexibility and robustness. APS is applied to several econometric and statistical examples. The empirical results for a regression model with scale contamination, an ARMA-GARCH-Student t model with near cancellation of roots and heavy tails, a mixture model for economic growth, and a nonlinear threshold model for industrial production growth confirm the practical flexibility and robustness of APS. Creation-Date: 2002-09-17 File-URL: https://repub.eur.nl/pub/555/feweco20020917131720.pdf File-Format: application/pdf Series: RePEc:ems:eureir Number: EI 2002-27 Keywords: Importance sampling, Markov chain Monte Carlo, Polar coordinates Handle: RePEc:ems:eureir:555