A Bayesian Analysis of Structural Changes with an Application to the Displacement Effect

In this paper we propose a new approach to the problem of structural change from a Bayesian point of view. Our approach is based on a hierarchical model with a Dirichlet process prior. A notable feature of the Dirichlet process is its discreteness which is useful for detecting structural changes. The approach developed in the paper is illustrated using simulated and real data sets. For the real data set, we examine possible structural changes in government expenditure in Japan using the annual data from 1957 to 1995. It is shown that two structural breaks occurred, before and after the first oil crisis