Around and Around: The Expectations Hypothesis

We show how to construct models of the term structure of interest rates in which the expectations hypothesis holds. McCulloch (1993) presents such a model, thereby contradicting an assertion by Cox, Ingersoll, and Ross (1981), but his example is Gaussian and falls outside the class of finite-dimensional Markovian models. We generalize McCulloch's model in three ways: (i) We provide an arbitrage-free characterization of the unbiased expectations hypothesis in terms of forward rates; (ii) we extend this characterization to a whole class of expectations hypotheses; and (iii) we show how to construct finite-dimensional Markovian and non-Gaussian examples.     

Note on a new method of construction of mortality tables when the number of lives exposed to risk is unknown

Abstract

It has been known for some time that the d^bx column in a mortality table can be considered as a compound frequency curve with a limited number of maxima and minima. From a theoretical point of view this is of course a self evident conclusion which follows directly from the so-called genetic theory of frequency originally introduced by Laplace. He showed that any frequency distribution can be considered or generated as the sum of a very large number of elementary errors, referrable to several sources of error, each group or error having its own peculiar law of error. While the pure theory of the generation of frequency curves from such secondary sources of elementary errors is simple enough, the inverse and essentially practical problem of decomposing a compound frequency curve into its component or constituent elements is by no means simple and often presents great difficulties, especially if certain restrictions are imposed upon the component curves. An example of such restrictions would be the requirement that all the component curves should be normal Laplacean probability curves.     

Combination schemes for turning point predictions

We propose new forecast combination schemes for predicting turning points of business cycles. The proposed combination schemes are based on the forecasting performances of a given set of models with the aim to provide better turning point predictions. In particular, we consider predictions generated by autoregressive (AR) and Markov-switching AR models, which are commonly used for business cycle analysis. In order to account for parameter uncertainty we consider a Bayesian approach for both estimation and prediction and compare, in terms of statistical accuracy, the individual models and the combined turning point predictions for the United States and the Euro area business cycles.     

Professional Ethics in a Virtual World: The Impact of the Internet on Traditional Notions of Professionalism

Numerous articles in the popular press together with an examination of websites associated with the medical, legal, engineering, financial, and other professions leave no doubt that the role of professions has been impacted by the Internet. While offering the promise of the democratization of expertise – expertise made available to the public at convenient times and locations and at an affordable cost – the Internet is also driving a reexamination of the concept of professional identity and related claims of expertise and standards of integrity.This paper begins with a presentation of case studies illustrating the ease by which impostors infiltrate the ranks of professionals. Reports of individuals masquerading as professionals via the Internet often reveal that these imposters cause harm to the unwary victims who rely on assertions of professional expertise. Such reports motivated the authors to examine the origins and evolution of the traditional roles of professions and professionals in today’s society, as well as question how, or whether, the standards for professional practice have been adapted to the challenges posed by technology, i.e., do statements of professional ethics provide a ‘guiding light’ for practitioners and their clients in the cyber age? The authors challenge the professions to consider the notion that technology forces a confrontation between the guild-like aspects of a profession that have served, on the one hand, to protect a profession from encroachment and, on the other hand, have purportedly protected the public.The authors conclude by presenting an examination of websites that show recognition of the challenges that the Internet poses to professionalism, as we have known it. Detailed discussion of the websites of two professions illustrates different approaches to responding to these challenges.