The Acceptability and the Tolerability of Societal Risks: A Capabilities-based Approach

Abstract

In this paper, we present a Capabilities-based Approach to the acceptability and the tolerability of risks posed by natural and man-made hazards. We argue that judgments about the acceptability and/or tolerability of such risks should be based on an evaluation of the likely societal impact of potential hazards, defined in terms of the expected changes in the capabilities of individuals. Capabilities refer to the functionings, or valuable doings and beings, individuals are able to achieve given available personal, material, and social resources. The likely impact of a hazard on individuals' capabilities should, we argue, be compared against two separate thresholds. The first threshold specifies the minimum level of capabilities attainment that is acceptable in principle for individuals to have in the aftermath of a hazard over any period of time. This threshold captures the level that individuals' capabilities ideally should not fall below. A risk is acceptable if the probability that the attained capabilities will be less than the acceptable level is sufficiently small. In practice, it can be tolerable for some individuals to temporarily fall below the acceptable threshold, provided this situation of lower capabilities attainment is temporary, reversible, and the probability that capabilities will fall below a tolerability threshold is sufficiently small. This second, tolerable threshold delimits an absolute minimum level of capabilities attainment below which no individual in a society should ever fall, regardless of whether that level of capabilities attainment is temporary or reversible. In this paper, we describe and justify this Capabilities-based Approach to the acceptability and tolerability of risks. We argue that the proposed theoretical framework avoids the limitations in current approaches to acceptable risk. The proposed approach focuses the attention of risk analysts directly on what should be our primary concern when judging the acceptability and the tolerability of risks, namely, how risks impact the well-being of individuals in a society. Also, our Capabilities-based Approach offers a transparent, easily communicable way for determining the acceptability and the tolerability of risks.

Resilience indicators: opportunities for including distributive justice concerns in disaster management

“…Starting from the definition of risk used in engineering (probability times consequences), Murphy and Gardoni see a role for the capability approach in the conceptualization and assessment of consequences of hazardous scenarios (Murphy & Gardoni, 2012: p. 984). In terms of risk evaluation, Murphy and Gardoni (2008) distinguish between tolerable and acceptable threshold levels. The acceptable threshold level is the higher of the two and specifies the minimum level of capabilities that people should be able to enjoy over time.…”

Theories of Risk Management and Multiple Hazards: Thoughts for Engineers from Regulatory Policy

“…In the context of risk analysis, this means that decision-makers must make judgments about the acceptability of risks to various functionings (Murphy and Gardoni 2008). In general, this tie between capability definition and risk thresholds is a double-edged sword, much as monetization is for cost-benefit analysis, and provides at the same time strengths and challenges for the capability framework.…”

Engineering Decisions under Risk Averseness

“…These decision models are well understood and widely used; see for example [10,Chapter 12] for a discussion. Recent proposals centered on the capabilities of individuals after disasters also rely on probabilities of exceeding thresholds specifying essential needs [21,22,13,23]. However, there are two immediate concerns with failure probability models.…”