The state space model is widely used to handle time series data driven by related latent processes in many fields. In this article, we suggest a framework to examine the relationship between state space models and ARIMA models by examining the existence and positive-definiteness conditions...

We propose a framework covering multi-country and multi-generation diffusion processes. Our model focuses on choice-based diffusion model and we extend the model to incorporate heterogeneity of country. We decompose the choice probability for generation into two components; the first one is...

Testing the existence of unit root and/or level change is necessary in order to understand the underlying processes of time series. In many studies carried out so far, the focus was only on a single aspect of unit root and level change, therefore limiting a full assess to the given problems. Our...