Stochastic Conditional Duration Models with Mixture Processes

This paper studies a stochastic conditional duration (SCD) model with a mixture of distribution processes for financial asset’s transaction data. Specifically it imposes a mixture of two positive distributions on the innovations of the observed duration process, where the mixture component distributions could be either Exponential, Gamma or Weibull. The model also allows for correlation between the observed durations and the logarithm of the latent conditionally expected durations in order to capture a leverage effect known to exist in the equity market. In addition the proposed mixture SCD model is shown to be able to accommodate possibly heavy tails of the marginal distribution of durations. Novel Markov Chain Monte Carlo (MCMC) algorithms are developed for Bayesian inference of parameters and duration forecasting of these models. Simulation studies and empirical applications to two stock duration data sets are provided to assess the performance of the proposed mixture SCD models and the accompanying MCMC algorithms.