Further Thoughts on the Utility of Risk Matrices

Authors

  • David J. Ball,

    1. Middlesex University, School of Science and Technology, Centre for Decision Analysis and Risk Management, London, UK
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  • John Watt

    Corresponding author
    1. Middlesex University, School of Science and Technology, Centre for Decision Analysis and Risk Management, London, UK
    • Address correspondence to John Watt, Middlesex University, School of Science and Technology, Centre for Decision Analysis and Risk Management, The Burroughs, Hendon, London, NW4 4BT, UK; J.Watt@mdx.ac.uk.

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Abstract

Risk matrices are commonly encountered devices for rating hazards in numerous areas of risk management. Part of their popularity is predicated on their apparent simplicity and transparency. Recent research, however, has identified serious mathematical defects and inconsistencies. This article further examines the reliability and utility of risk matrices for ranking hazards, specifically in the context of public leisure activities including travel. We find that (1) different risk assessors may assign vastly different ratings to the same hazard, (2) even following lengthy reflection and learning scatter remains high, and (3) the underlying drivers of disparate ratings relate to fundamentally different worldviews, beliefs, and a panoply of psychosocial factors that are seldom explicitly acknowledged. It appears that risk matrices when used in this context may be creating no more than an artificial and even untrustworthy picture of the relative importance of hazards, which may be of little or no benefit to those trying to manage risk effectively and rationally.

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