Some probability problems associated with cross-impact analysis

Abstract Various probability models are discussed which may be applied to Cross-Impact analysis. The bulk of this article is concerned with what is currently the most commonly employed model that utilizes marginal probabilities and either simple conditional probabilities or ”impacts“. Requirements for admissible probability sets are given and some misgivings about current practices are discussed. Bounds are given for the joint occurrence or non-occurrence of a number of events which could replace the Monte Carlo generation currently in use. It is concluded that the multitude of probability problems associated with Cross-Impact analysis are such as to preclude its use as a quantitative technique in its present form although its use as a vehicle for promoting discussion can still be recommended and some of the results can serve as a rough guide in forecasting.