In finance, durations between successive transactions are usually modelled by the autoregressive conditional duration model based on a continuous distribution omitting frequent zero values. Zero durations can be caused by either split transactions or independent transactions. We propose a...

We propose Midastar models by combining the Mixed Data Sampling (MIDAS) and the threshold autoregression (TAR). The Midastar model of the first kind is designed for a low frequency target variable and a high frequency threshold variable. The proposed model can detect threshold effects...

In this paper, we suggest and evaluate specification tests to test the validity of the conditional mean function implied by Autoregressive Conditional Duration (ACD) models. We propose Lagrange multiplier tests against sign bias alternatives, various types of conditional moment tests and...

We explore some aspects of the analysis of latent component structure in non-stationary time series based on time-varying autoregressive (TVAR) models that incorporate uncertainty on model order. Our modelling approach assumes that the AR coefficients evolve in time according to a random walk...

Business cycles and economic growth have long been studied separately, hindering understanding of the nature and causes of economic fluctuations and growth. Here, we present an economic model that incorporates both deterministic trends and persistent fluctuations, derived from a general economic...