We obtain an invariance principle for the two-dimensional Brownian sheet where the underlying random field need not be independent or stationary. We also provide a basic demonstration of its application towards spatial unit root testing

Stochastic mortality models seek to forecast future mortality rates; thus, it is apparent that the objective variable should be the mortality rate expressed in the original scale. However, the performance of stochastic mortality models-in terms, that is, of their goodness-of-fit and prediction...

In a recent paper "Stochastic Chain-Ladder Reserving with Modeled General Inflation", the effects of modeled general inflation on non-life claims reserving were studied using, along with the so called "market approach", a stochastic two-factor market model, characterized by deterministic...

Despite the growing interest in realized stochastic volatility models, their estimation techniques, such as simulated maximum likelihood (SML), are computationally intensive. Based on the realized volatility equation, this study demonstrates that, in a finite sample, the quasi-maximum likelihood...