Risk compensation during COVID-19: The impact of face mask usage on social distancing.

To reduce the spread of COVID-19, governments around the world have recommended or required minimum physical distancing between individuals, as well as either mandating or recommending the use of face coverings (masks) in certain circumstances. When multiple risk reduction activities can be adopted, people may engage in risk compensation by responding to a reduced (perceived) risk exposure due to one activity by increasing risk exposure due to another. We tested for risk compensation in two online experiments that investigated whether either wearing a mask or seeing others wearing masks reduced physical distancing. We presented participants with stylized images of everyday scenarios involving themselves with or without a mask and a stranger with or without a mask. For each scenario, participants indicated the minimum distance they would keep from the stranger. In line with risk compensation, we found that participants indicated they would stand, sit, or walk closer to the stranger if either of them was wearing a mask. This form of risk compensation was stronger for those who believed masks were effective at preventing catching or spreading COVID-19, and for younger (18-40 years) compared to older (over 65 years) participants. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The efficiency-equity trade-off, self-interest, and moral principles in health and safety valuation.

Policy makers try to take account of public preferences when making trade-offs between policy options. Yet most estimates of the value of health and safety reflect only individuals' self-interested preferences, neglecting their preferences over the distribution of public resources. We conduct an experiment in which participants choose between policy options that differ in their efficiency (expected number of fatalities or cases of ill health they would prevent) and their equity (defined in terms of the balance of risk reductions for different sections of the population). The policy options were framed as interventions to improve a hypothetical city's water supply that would reduce the risk of death or ill health for people in different areas of the city to varying degrees. In order to examine whether self-interest would affect the trade-offs, we asked half of the sample about scenarios where they would personally benefit from some options. Our results suggest that efficiency is the most important single factor determining preferences between policy options, but decisions were influenced almost as much by equity as by efficiency. The effect of self-interest was smaller than that of the general concern for efficiency. We also elicited participants' stated moral principles regarding trade-offs between equity, efficiency and self-interest, and found that their expressed principles were well-aligned with their choices. Our findings contribute to the growing evidence that distributional concerns matter when evaluating health interventions.

Boundedly rational expected utility theory.

We build a satisficing model of choice under risk which embeds Expected Utility Theory (EUT) into a boundedly rational deliberation process. The decision maker accumulates evidence for and against alternative options by repeatedly sampling from her underlying set of EU preferences until the evidence favouring one option satisfies her desired level of confidence. Despite its EUT core, the model produces patterns of behaviour that violate standard EUT axioms, while at the same time capturing systematic relationships between choice probabilities, response times and confidence judgments, which are beyond the scope of theories that do not take deliberation into account.

Noisy preferences in risky choice: A cautionary note.

We examine the effects of multiple sources of noise in risky decision making. Noise in the parameters that characterize an individual's preferences can combine with noise in the response process to distort observed choice proportions. Thus, underlying preferences that conform to expected value maximization can appear to show systematic risk aversion or risk seeking. Similarly, core preferences that are consistent with expected utility theory, when perturbed by such noise, can appear to display nonlinear probability weighting. For this reason, modal choices cannot be used simplistically to infer underlying preferences. Quantitative model fits that do not allow for both sorts of noise can lead to wrong conclusions. (PsycINFO Database Record

Quantitative tests of the Perceived Relative Argument Model: reply to Guo and Regenwetter (2014).

Guo and Regenwetter (2014) took the perceived relative argument model, added various auxiliary assumptions of their own about the utility of money, made assumptions about possible stochastic specifications, and tested the various combined models against data from an experiment they conducted. However, their modeling assumptions were questionable and their experiment was unsatisfactory: The stimuli omitted crucial information, the incentives were weak, and the task load was excessive. These shortcomings undermine the quality of the data, and the study provides no new information about the scope and limitations of the perceived relative argument model or its performance relative to other models of risky choice. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

The social value of a QALY: raising the bar or barring the raise?

BACKGROUND: Since the inception of the National Institute for Health and Clinical Excellence (NICE) in England, there have been questions about the empirical basis for the cost-per-QALY threshold used by NICE and whether QALYs gained by different beneficiaries of health care should be weighted equally. The Social Value of a QALY (SVQ) project, reported in this paper, was commissioned to address these two questions. The results of SVQ were released during a time of considerable debate about the NICE threshold, and authors with differing perspectives have drawn on the SVQ results to support their cases. As these discussions continue, and given the selective use of results by those involved, it is important, therefore, not only to present a summary overview of SVQ, but also for those who conducted the research to contribute to the debate as to its implications for NICE. DISCUSSION: The issue of the threshold was addressed in two ways: first, by combining, via a set of models, the current UK Value of a Prevented Fatality (used in transport policy) with data on fatality age, life expectancy and age-related quality of life; and, second, via a survey designed to test the feasibility of combining respondents' answers to willingness to pay and health state utility questions to arrive at values of a QALY. Modelling resulted in values of £10,000-£70,000 per QALY. Via survey research, most methods of aggregating the data resulted in values of a QALY of £18,000-£40,000, although others resulted in implausibly high values. An additional survey, addressing the issue of weighting QALYs, used two methods, one indicating that QALYs should not be weighted and the other that greater weight could be given to QALYs gained by some groups. SUMMARY: Although we conducted only a feasibility study and a modelling exercise, neither present compelling evidence for moving the NICE threshold up or down. Some preliminary evidence would indicate it could be moved up for some types of QALY and down for others. While many members of the public appear to be open to the possibility of using somewhat different QALY weights for different groups of beneficiaries, we do not yet have any secure evidence base for introducing such a system.

Modeling choice and valuation in decision experiments.

This article develops a parsimonious descriptive model of individual choice and valuation in the kinds of experiments that constitute a substantial part of the literature relating to decision making under risk and uncertainty. It suggests that many of the best known "regularities" observed in those experiments may arise from a tendency for participants to perceive probabilities and payoffs in a particular way. This model organizes more of the data than any other extant model and generates a number of novel testable implications which are examined with new data.

Trying to estimate a monetary value for the QALY.

In this paper we study the feasibility of estimating a monetary value for a QALY (MVQ). Using two different surveys of the Spanish population (total n = 892), we consider whether willingness to pay (WTP) is (approximately) proportional to the health gains measured in QALYs. We also explore whether subjects' responses are prone to any significant biases. We find that the estimated MVQ varies inversely with the magnitude of health gain. We also find two other (ir)regularities: the existence of ordering effects; and insensitivity of WTP to the duration of the period of payment. Taken together, these effects result in large variations in estimates of the MVQ. If we are ever to obtain consistent and stable estimates, we should try to understand better the sources of variability found in the course of this study.