Improving the risk–risk trade-off method for use in safety project appraisal responses

Abstract

The risk-risk trade-off method is a technique used to elicit the relative trade-off between changes in morbidity and mortality risks in stated preference surveys. The responses can be used to inform the (relative) values or weights that should be given to different accidents in cost-benefit analyses of road-safety projects that reduce the risk of death or injury. While the method has some distinct advantages over eliciting direct monetary measures of value, it is likely to suffer from similar problems that are found in other stated preference surveys, which might mitigate against its more widespread use. This study explores this issue, but shows that the estimates from a risk-risk trade-off study can be improved by employing a pre-survey learning experiment in which respondents make incentivised risky choices and also using a frame that focuses on the total risk or risks that respondents face, thereby broadening the toolkit available to measure preferences over road-safety interventions.

A Novel Application of Risk–Risk Tradeoffs in Occupational Health: Nurses’ Occupational Asthma and Infection Risk Perceptions Related to Cleaning and Disinfection during COVID-19

“…Distributions appeared bimodal, with the largest proportions being for the smallest and largest risk choices ( Supplemental Materials ). Risk–risk tradeoff tipping point estimation is known for being prone to anchoring or reference point effects [ 15 ]. Anchoring describes a bias in which individuals’ decisions are biased towards the information they first received about the scenario [ 20 ].…”

“…Reference point effects exist when an individual perceives something as a gain or loss relative to a reference point, where a perceived gain may lead to risk-averse behavior and perceived loss may lead to risk-seeking behavior [ 21 ]. The use of a list to elicit the risk–risk tradeoff tipping points, as opposed to soliciting open-ended responses, may introduce such framing effects [ 15 , 22 ], where participants can gravitate towards middle choices or see the lower and upper bound options as “reasonable” because they are presented options [ 22 ]. While participants did not seem to gravitate towards middle responses when choosing tipping points, this may have affected the distribution of scores for self-perceived willingness to take risks, where the average score between 1 and 10 was 5.4 (SD = 2.0).…”

“…Point estimates of baseline risks were first presented for the two outcomes as an expected number of cases per 100,000 people or 50 million people, depending upon the size of the risk (chosen so that ≥1 person per number of people was reported for ease of interpretation). Following a standard experimental design [ 14 , 15 , 16 ] with roots in judgement decision making [ 17 , 18 ], participants were then presented with the choice to opt to move from Hospital 1 to a different hospital, where they were required either to choose Hospital 2 or 3 or to indicate they were happy with either option (i.e., not able to choose Hospital 1). It should be noted that switching to a different hospital was implemented in scenarios to model previous risk–risk tradeoff surveys that utilize a change in location or “area” [ 15 ].…”

“…Following a standard experimental design [ 14 , 15 , 16 ] with roots in judgement decision making [ 17 , 18 ], participants were then presented with the choice to opt to move from Hospital 1 to a different hospital, where they were required either to choose Hospital 2 or 3 or to indicate they were happy with either option (i.e., not able to choose Hospital 1). It should be noted that switching to a different hospital was implemented in scenarios to model previous risk–risk tradeoff surveys that utilize a change in location or “area” [ 15 ]. However, in real-world scenarios, nurses are unlikely to work at different hospitals due to C&D exposure; rather, they may change locations due to pay, leadership, workplace culture, and myriad factors.…”

A risk–risk trade‐off assessment of climate‐induced mortality risk changes

“…To estimate preferences for mortality risk changes, we apply the RRTO approach originally developed by Viscusi et al (1991). This is a nonmonetary, relative valuation approach that has been applied successfully across a number of contexts and used to analyze the trade-offs over fatal and nonfatal risk changes, such as chronic illnesses (McDonald et al, 2016;Magat et al, 1996;Van Houtven et al, 2008;Viscusi et al, 1991), traffic accidents (Chilton et al, 2006;Nielsen et al, 2019), mass shootings and terrorist attacks (Dalafave & Viscusi, 2021;Viscusi, 2009), and natural disaster deaths compared to other risks, such as terrorism and traffic (Viscusi, 2009). One paper has examined environmental fatalities but focuses only on preference ratings for risks (Clarke et al, 1997).…”