We consider a random design model based on independent and identically distributed pairs of observations (Xi, Yi), where the regression function m(x) is given by m(x) = E(Yi|Xi = x) with one independent variable. In a nonparametric setting the aim is to produce a reasonable approximation to the...

This paper investigates the effects of ordinal regressors in linear regression models. Each ordered categorical variable is interpreted as a rough measurement of an underlying continuous variable as it is often done in microeconometrics for the dependent variable. It is shown that using ordinal...

A time series analysis was performed on medical scheme statistics with the aim of determining current and future demographic and economic trends. This would enable one to reach a better perspective on the current and future financial dilemma presently experienced by medical schemes. Data for the...

Statistical flowgraphs represent multistate semi-Markov processes using integral transforms of transition time distributions between adjacent states; these are combinedalgebraically and inverted to derive parametric estimates for first passage time distributions between nonadjacent states. This...

We apply semiparametric efficient estimation procedures for a seemingly unrelated regression model where the multivariate error density is elliptically symmetric to study the efficiency of the foreign exchange market. We consider both cointegrating regressions and standard stationary...

In an increasingly competitive environment, firms have to optimally adjust both their allocation of input factors and their technology portfolio. The latter determines economies of scope and scale in future research and production. The aim of this dissertation is to achieve better insight into...

This dissertation consists of three stand-alone research papers, all of which treat the topic of estimation and dynamic modelling of multivariate volatility by employing the information contained in high-frequency data, which became available in the last 10 - 15 years. The main focus of all...