Tailored Randomized-block MCMC Methods for Analysis of DSGE Models∗
Tailored Randomized-block MCMC Methods for Analysis of DSGE Models∗
复制标题
用于 DSGE 模型分析的定制随机块 MCMC 方法*
DOI:
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发表时间:
2009
期刊:
影响因子:
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通讯作者:
Srikanth Ramamurthy
中科院分区:
文献类型:
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作者:
S. Chib;Srikanth Ramamurthy
In this paper we develop new Markov chain Monte Carlo schemes for Bayesian estimation of DSGE models. The motivation for our work arises from some of the shortcomings of the single block random walk Metropolis Hastings (M-H) algorithm (RW-MH), the sampling method that has been used to date in this context. In our basic tailored randomized block (TaRB-MH) algorithm, the parameters of the model are randomly clustered at every iteration into an arbitrary number of blocks. Then each block is sequentially updated through an M-H step. Furthermore, the proposal density for each block is tailored to the location and curvature of the target density based on the output of simulated annealing, following Chib and Greenberg (1994, 1995) and Chib and Ergashev (2008). We also provide an extension of the TaRB-MH algorithm for sampling multi-modal distributions. In this version, which we refer to as the TaRBMJ-MH algorithm, at a pre-specified mode jumping iteration (say every 100th), a single-block proposal is generated from one of the modal regions using a mixture proposal density, and this proposal is then accepted according to an M-H probability of move. At the non-mode jumping iterations, the draws are obtained by applying the TaRB-MH algorithm. The methodological developments are completed by showing how the approach in Chib (1995) and Chib and Jeliazkov (2001) can be adapted to these sampling schemes for estimating the model marginal likelihood. We illustrate our methods with the aid of stylized problems and three DSGE models that have appeared in the literature. The first is the model in Ireland (2004) where we show that the TaRB-MH algorithm is more reliable and efficient than the RW-MH algorithm. Our second example is the model in An and Schorfheide (2007). The posterior distribution in this model is more challenging to simulate on account of multiple modes. As shown by these authors, the RW-MH algorithm is unable to jump from the low modal region to the high modal region, and vice-versa. The TaRBMJ-MH ∗We gratefully acknowledge the support from Center for Research in Economics and Strategy (CRES), in the Olin Business School, Washington University in St. Louis. †Chib: Olin Business School, Washington University in St. Louis, Campus Box 1133, 1 Bookings Drive, St. Louis, MO 63130 (e-mail: chib@wustl.edu); Ramamurthy: Department of Economics, Washington University in St. Louis, Campus Box 1208, 1 Bookings Drive, St. Louis, MO 63130 (e-mail: sramamur@artsci.wustl.edu).