A risk-risk trade-off assessment of climate-induced mortality risk changes.

The impact of climate change on human health was identified as a priority for the UN COP26 conference. In this article, we consider climate-induced changes to mortality risks and how to incorporate these formally in the policy appraisal process. In the United Kingdom (UK), the Value of Statistical Life (VSL) is used to monetarize the benefits of policies to reduce mortality risks but it remains an open, empirical question as to whether the current VSL (£2.14 million per fatality prevented, December 2021 values) for traffic accidents should be applied in other contexts without any modification and particularly for extreme weather event fatalities. Using a representative sample of the UK population, we aim to estimate and better understand the trade-offs people make when comparing mortality risks, drawing on psychological insights from construal level and regulatory focus theories. We design a stated preference survey using a relative valuation framework with nonmonetary, risk-risk trade-off questions between extreme weather event and traffic accident mortality risks. We find evidence of an extreme weather event risk premium of 1.2-1.6 (implying a climate-related VSL of £2.52-£3.41 million). We also find that participants who are psychologically close to climate change (based on construal level theory), weigh reducing extreme weather event mortality risks almost two times that of reducing traffic accident mortality risks.

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.

BACKGROUND: Nurses face the risk of new onset occupational asthma (OA) due to exposures to cleaning and disinfection (C&D) agents used to prevent infections in healthcare facilities. The objective of this study was to measure nurses' preferences when presented with simultaneous OA and respiratory viral infection (e.g., COVID-19) risks related to increased/decreased C&D activities. METHODS: Nurses working in healthcare for ≥1 year and without physician-diagnosed asthma were recruited for an online anonymous survey, including four risk-risk tradeoff scenarios between OA and respiratory infection with subsequent recovery (Infect and Recovery) or subsequent death (Infect and Death). Nurses were presented with baseline risks at hypothetical "Hospital 1", and were asked to choose Hospital 2 (increased OA risk to maintain infection risk), Hospital 3 (increased infection risk to maintain OA risk), or indicate that they were equally happy. RESULTS: Over 70% of nurses were willing to increase infection risk to maintain baseline OA risk if they were confident they would recover from the infection. However, even when the risk of infection leading to death was much lower than OA, most nurses were not willing to accept a larger (but still small) risk of death to avoid doubling their OA risk. Age, work experience, and ever having contracted or knowing anyone who has contracted a respiratory viral infection at work influenced choices. CONCLUSIONS: We demonstrate the novel application of a risk-risk tradeoff framework to address an occupational health issue. However, more data are needed to test the generalizability of the risk preferences found in this specific risk-risk tradeoff context.

Association between time preference, present-bias and physical activity: implications for designing behavior change interventions.

BACKGROUND: The decision to initiate or maintain a healthy habit, such as physical activity involves a trade-off between a short-term cost, such as time and effort, which are commonly identified as barriers to physical activity, and a long-term health benefit. Research suggests that individual time preference may be associated with unhealthy behaviors. However, empirical evidence of this for physical activity is scant. This study investigated the relationship between time preference and physical activity, and how this might influence behavior change. METHODS: Employees (n = 176; mean age 42.2 years) who participated in a physical activity intervention were invited to take part in a behavioral economic field experiment. Two economic experiments, using multiple price lists and monetary trade-off tables involving real money choices, were conducted face-to-face with participants to measure the two components of time preference, namely present-bias and discount rate. Together with individual risk preferences, these three variables were jointly estimated by maximum likelihood. These three parameters were expressed as a linear function of the levels of physical activity while controlling for socio-demographic variables within the same maximum likelihood framework. RESULTS: Those who were present-biased and who had higher discount rates did significantly less physical activity than their patient and non present-biased counterparts. A 3% lower discount rate and 1.14 unit decrement in the present-bias parameter was associated with a 30 min increase of physical activity per week. This negative association was more significant for certain sub-groups, such as younger and married adults and those with higher staff grade and those who have children. Participants who dropped out of the study earlier were more present-biased. CONCLUSIONS: Results demonstrated that discount rate and present-biasedness have a significant impact on physical activity levels. Such concepts have been largely overlooked and underutilized in physical activity interventions. Promising implications include 1) utilizing individuals' time preferences to better target interventions; 2) taking account of time preferences in the intervention design; 3) interventions attempting to correct for present-biasedness.

Comparing Increments in Utility of Health: An Individual-based Approach.

BACKGROUND: Many economic evaluations of health care changes rely on quality-adjusted life year (QALY) estimates. Notably, though, the QALY approach values health states rather than changes in health states. Hence, a gain in utility of health is only indirectly valued through an ex ante preference elicitation of health states and the subsequent subtraction of health state values from one another, rather than being valued directly. There is therefore an underlying assumption that individuals, from an ex ante perspective ceteris paribus, would be indifferent between equal utility increments from health states with different baseline utilities. OBJECTIVE: The aim of this paper is to develop a method that would allow us to measure individual-based preferences over utility increments from different baselines. We elicit our data using face-to-face interviews on a sample of UK individuals. RESULTS: Overall, we find that gains of "equal" utility increments from different baselines are not found to be equally preferable by the individual. CONCLUSIONS: The results indicate that the subtraction approach could lead to sub-optimal resource allocations and suggest that a new approach which values health changes directly would better reflect individual preferences. This paper provides the foundations for a method to achieve this.