How to deal with dissent among experts. Risk evaluation of EMF in a scientific dialogue

This article describes the results of a scientific discourse which aimed at exploring the reasons for differences in expert health risk assessment of radio frequency electromagnetic fields of mobile telephony.

It starts with describing the structure of the discourse. Then, the reasons for the conflicting risk assessments are discussed. Differences are due to the selection and evaluation of relevant scientific studies by applying different scientific quality standards, to the methods used for generating a research synthesis and an overall risk evaluation. Consensus could be achieved regarding the selection of and the quality requirements for the scientific studies used for risk assessment as well as their significance for risk evaluation. However, dissent remained about the synthesis of scientific evidence into an overall risk evaluation and about the relevance of the precautionary principle for risk evaluation and its implications for the risk assessment framework.

Based on the analysis of these problems, a transparent, consistent and rational procedure for risk assessment is suggested to facilitate a risk characterization which better meets the demands of policy making and the public for an appropriate risk evaluation.     

ACQUISITION OF INFORMATION TO DIVERSIFY CONTRACTUAL RISK*

Are hedging transactions that diversify a manager’s compensation risk detrimental to incentives, or can they improve contracting efficiency? If hedging provides efficiency benefits, should the manager or the firm undertake it? In our model, both the firm and the manager can trade financial portfolios to diversify the manager’s compensation risk. Prior to the portfolio selection, the parties need to acquire information on how different financial portfolios fit their diversification purposes. We illustrate that financial portfolios correlated with firm‐specific risk improve contracting efficiency. For equal information costs, it is optimal for the firm to undertake the hedging on the manager’s behalf.     

Regulations for the Eighth International Congress of Actuaries

Abstract

The present paper proposes and investigates a procedure for numerical evaluation of the transition probabilities for a time-inhomogeneous Markov process when the intensities are known (estimated). The procedure is based on Taylor-expansion of the transition probabilities linked with the Chapman-Kolmogorov equations.     

Persistent mispricing in a recently opened emerging index futures market: Arbitrageurs invited

The purpose of this study is to analyze the persistent, typically negative, mispricing in the new stock index futures market in Turkey, which has amounted to 5–8%, several multiples of transaction costs. The observations suggest that it is the outcome of a combination of practical difficulties of shorting in the spot stock market, behavioral effects, and insufficient arbitrage. The magnitude of the mispricing and the absence of arbitrage make behavioral effects more visible and provide a unique opportunity to examine extant behavioral hypotheses. Results confirm effects such as disposition and/or conservatism with the mispricing negatively related to past returns, but unrelated to future returns. Finally, an orderly weakening of the negative relation to past returns and behavioral effects is observed, suggesting that such effects will diminish as the market matures. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:218–243, 2009