This paper explores and compares the empirical distribution of the US dollar–deutsche mark exchange rate returns with well-known continuous-times processes at different frequencies. We use a variety of parametric models to simulate the unconditional density of the exchange rate returns at...

Each of the following sections carries one central thought, often summarised in one (bold-face) sentence. Together, these statements give an overview of some major long term issues of sustainable use of energy which humanity must face. No effort is made to argue all points, to be exhaustive, or...