De meting van maatschappelijke voorkeuren voor gezondheid(szorg) vanuit een gedragseconomisch perspectief

Het is wenselijk om de voorkeuren van mensen met betrekking tot de afruil tussen efficiëntie en rechtvaardigheid van gezondheidszorg (in termen van het gebruik van zorg) op een zuivere manier te meten. De beleidsmaker krijgt hierdoor de mogelijkheid om beslissingen te nemen die in het belang van de maatschappij zijn. Dit artikel demonstreert hoe inzichten uit de gedragseconomie kunnen worden gebruikt om maatschappelijke voorkeuren voor de verdeling van zorgmiddelen beter te kunnen meten. Een praktisch voorbeeld toont de relevantie van deze nieuwe inzichten voor de allocatie van schaarse middelen in de gezondheidszorg aan

De TTO-methode en correctie voor tijdsvoorkeur

Inleiding: De time tradeoff (TTO-) methode is een veelgebruikte methode voor het waarderen van gezondheidstoestanden (Dolan, 1997; Dolan e.a., 1996). In een TTO dienen individuen een afweging te maken tussen kwaliteit van leven en levensduur. Een typische TTO-procedure omvat een afweging tussen het leven in een bepaalde imperfecte gezondheidstoestand gedurende tien jaar en het leven in perfecte gezondheid gedurende een periode van minder dan tien jaar, waarna in beide gevallen dood volgt

Studies on Intertemporal Preferences with Applications to Health Economics

Economic benefits are often received at different points in time. There are numerous examples of economic applications where the outcomes occur at multiple points in time. Among these are the savings decisions of households, the environmental policies of countries, investment decisions of firms, health-related decisions of individuals, and educational activities of students. In the majority of these cases, future outcomes are valued lower than similar present outcomes, i.e. there is positive time preference. There are several reasons for this behavior. One reason is that the future is almost always surrounded by uncertainty, whilst outcomes received immediately or in the nearer future are more certain. This translates into the discounting of future outcomes. Second, utility is often concave in outcomes (diminishing marginal utility). This means that more units of a particular outcome give less additional utility the more one already possesses of that outcome or the more one has already consumed of it. A second cup of coffee, for example, often gives less utility than the first one. Because wealth is increasing over time due to economic growth, people have more possibilities to consume in the future than in the present. The utility of this extra consumption does, however, not increase proportionally with the increase of consumption, so that future outcomes give less utility than similar present outcomes

Good things come to those who wait—Decreasing impatience for health gains and losses

Historically, time preferences are modelled by assuming constant discounting, which implies a constant level of impatience. The prevailing empirical finding, however, is decreasing impatience (DI), meaning that levels of impatience decrease over time. Theoretically, such changes in impatience are crucial to understand behavior and self-control problems. Very few methods exist to measure DI without being restricted to or confounded by certain assumptions about the discounting function or utility curve. One such measure is the recently introduced DI-index, which has been applied to both monetary and health outcomes. The DI-index quantifies the deviation from constant impatience and

Intertemporal Tradeoffs for Gains and Losses: An Experimental Measurement of Discounted Utility

This paper is the first to measure utility in intertemporal choice and presents new and more robust evidence on the discounting of money outcomes. Our measurement method is parameterfree in the sense that it requires no assumptions about utility or discounting. We found that intertemporal utility was concave for gains and convex for losses, consistent with a hypothesis put forward by Loewenstein and Prelec (1992). Utility in intertemporal choice was close to utility in decision under risk and uncertainty, suggesting that there may be one unifying concept of utility that applies to all of economics. The existence of one concept of utility is important for applied economics, because it largely reduces data requirements. Discount rates declined over time, but less so than has been observed in previous studies that assumed linear utility. Of the main discounted utility models, Loewenstein and Prelec’s (1992) generalized hyperbolic discounting model best fitted our data. The widely-used quasi-hyperbolic model fitted the data only slightly better than constant discounting. Finally, we obtained evidence of an asymmetry in discounting between gains and losses, which, in contrast with earlier findings, cannot be explained by a framing effect

Time-Tradeoff Sequences For Analyzing Discounting And Time Inconsistency

ABSTRACT. This paper introduces time-tradeoff (TTO) sequences as a new tool to analyze time inconsistency and intertemporal choice. TTO sequences simplify the measurement of discount functions, requiring no assumption about utility. They also simplify the qualitative testing of time inconsistencies, and allow for quantitative measurements thereof. TTO sequences can easily be administered using only pencil and paper. They readily show which subjects are most prone to time inconsistencies. We further use them to axiomatically analyze and empirically test (quasi-)hyperbolic discount functions. An experiment demonstrates the feasibility of measuring TTO sequences. Our data falsify (quasi-)hyperbolic discount functions and call for the development of models that can accommodate increasing impatience

New findings from the time trade-off for income approach to elicit willingness to pay for a quality adjusted life year

In this paper we empirically investigate how to appropriately model utility of wealth and health. We use a recently proposed alternative approach to value willingness to pay (WTP) for health, making use of trade-offs between income and life years or quality of life, which we extend to allow for a more realistic multiplicative utility function over health and money. Moreover, we show how reference-dependency can be incorporated into this model and derive its predictions for WTP elicitation. We propose three experimental elicitation procedures and test these in a feasibility study, analysing the responses under different assumptions about the discount rate. Several interesting results are reported: first, the data are highly skewed, but if we trim the 5% lowest and highest values, we obtain plausible WTP estimates. Second, the results differ considerably between procedures, indicating that WTP estimates are sensitive to the assumed utility function. Third, respondents appear to be loss averse for both health and money, which is consistent with assumptions from prospect theory. Finally, our results also indicate that respondents are more willing to trade quality of life than life years

A QALY loss is a QALY loss is a QALY loss

Evidence has accumulated documenting loss aversion for monetary and, recently, for health outcomes—meaning that, generally, losses carry more weight than equally sized gains. In the conventional Quality-Adjusted Life Year (QALY) models, which comprise utility for quality and length of life, loss aversion is not taken into account. When measuring elements of the QALY model, commonly, the (implicit) assumption is that utility for length and quality of life are independent. First attempts to quantify loss aversion for QALYs typically measured loss aversion in the context of life duration, keeping quality of life constant (or vice versa). However, given that QALYs are multi-attribute utilities, it may be possible that the degree of loss aversion is dependent on, or inseparable from, quality of life and non-constant. We test this assumption using non-parametric methodology to quantify loss aversion, under different levels of quality of life. We measure utility of life duration for four health states within subjects, and present the results of a robustness test of loss aversion within the QALY model. We find loss aversion coefficients to be stable at the aggregate level, albeit with considerable heterogeneity at the individual level. Implications for applied work on prospect theory within health economics are discussed

The corrective approach: policy implications of recent developments in QALY measurement based on prospect theory

Background and Objectives Common health state valuation methodology, such as time tradeoff (TTO) and standard gamble (SG), is typically applied under several descriptively invalid assumptions, for example, related to linear quality-adjusted life years (QALYs) or expected utility (EU) theory. Hence, the current use of results from health state valuation exercises may lead to biased QALY weights, which may in turn affect decisions based on economic evaluations using such weights. Methods have been proposed to correct responses for the biases associated with different health state valuation techniques. In this article we outline the relevance of prospect theory (PT), which has become the dominant descriptive alternative to EU, for health state valuations and economic evaluations. Methods and Results We provide an overview of work in this field, which aims to remove biases from QALY weights. We label this “the corrective approach.” By quantifying PT parameters, such as loss aversion, probability weighting, and nonlinear utility, it may be possible to correct TTO and SG responses for biases in an attempt to produce more valid estimates of preferences for health states. Through straightforward examples, this article illustrates the effects of this corrective approach and discusses several unresolved issues that currently limit the relevance of corrected weights for policy. Conclusions Suggestions for research addressing these issues are provided. Nonetheless, if validly corrected health state valuations become available, we argue in favor of using these in economic evaluations

Beliefs and Risk Perceptions About COVID-19: Evidence From Two Successive French Representative Surveys During Lockdown

Background: The outbreak of COVID-19 has been a major interrupting event, challenging how societies and individuals deal with risk. An essential determinant of the virus’ spread is a series of individual decisions, such as wearing face masks in public space. Those decisions depend on trade-offs between costs (or benefits) and risks, and beliefs are key to explain these. Methods: We elicit beliefs about the COVID-19 pandemic during lockdown in France by means of surveys asking French citizens about their belief of the infection fatality ratio (IFR) for COVID-19, own risk to catch the disease, risk as perceived by others, and expected prevalence rate. Those self-assessments were measured twice during lockdown: about 2 weeks after lockdown started and about 2 weeks before lockdown ended. We also measured the quality of these beliefs with respect to available evidence at the time of the surveys, allowing us to assess the calibration of beliefs based on risk-related socio-demographics. Finally, comparing own risk to expected prevalence rates in the two successive surveys provides a dynamic view of comparative optimism with respect to the disease. Results: The risk perceptions are rather high in absolute terms and they increased between the two surveys. We found no evidence for an impact of personal experience with COVID-19 on beliefs and lower risk perceptions of the IFR when someone in the respondent’s family has been diagnosed with a disease. Answers to survey 1 confirmed this pattern with a clear indication that respondents were optimistic about their chances to catch COVID-19. However, in survey 2, respondents revealed comparative pessimism. Conclusion: The results show that respondents overestimated the probabilities to catch or die from COVID-19, which is not unusual and does not necessarily reflect a strong deviation from rational behavior. While a rational model explains why the own risk to catch COVID-19 rose between the two surveys, it does not explain why the subjective assessment of the IFR remained stable. The comparative pessimism in survey 2 was likely due to a concomitant increase in the respondents’ perceived chances to catch the disease and a decreased expected prevalence rate