Stéphane Luchini

Preference Elicitation Under Oath

Eliciting sincere preferences for non-market goods remain a challenge due to the discrepency between hypothetical and real behavior and false zeros. The gap arises because people either overstate hypothetical values or understate real commitments or a combination of both. Herein we examine whether the traditional real-world institution of the solemn oath can improve preference elicitation. Applying the social psychology theory on the oath as a truth-telling-commitment device, we ask our bidders to swear on their honour to give honest answers prior to participating in an incentive-compatible second-price auction. The oath is an ancillary mechanism to commit bidders to bid sincerely in a second-price auction. Results from our induced valuation testbed treatments suggest that the oath-only auctions outperform all our other auctions (real and hypothetical). In our homegrown valuation treatments eliciting preferences for dolphin protection, the oath-only design induced people to treat as binding both their experimental budget constraint (i.e., lower values on the high end of the value distribution) and participation constraint (i.e., positive values in place of the zero bids used to opt-out of auction). Based on companion treatments, we show the oath works through an increase in the willingness to tell the truth, due to a strengthening of the intrinsic motivation to do so.

The impact of information on non-health attributes on willingness to pay for multiple health care programmes

Despite the acceptance that health gain is the most important attribute of health care, other aspects of health care may affect utility. The aim of this paper is to report an experiment to test the impact of providing different levels of information in the context of the EuroWill study, a joint contingent valuation (CV) of multiple health programmes. Three hundred and three respondents were simultaneously asked for their willingness-to-pay (WTP) for three health care programmes: more heart operations, a new breast cancer treatment and a helicopter ambulance service. To test for the impact of variation in information, three versions of one of the programmes (heart) were provided. Results show that WTP for all three programmes tended to be significantly higher for respondents who were provided additional positive information about the heart programme. Our results show that CV of health care programmes, which only take into account medical outcomes, may lead to the value of such programmes not being adequately estimated, and that the impact of information may even be more decisive in the context of joint evaluation of multiple, rather than single, programmes.

Impact of information on intentions to vaccinate in a potential epidemic: Swine-origin Influenza A (H1N1).

Vaccination campaigns to prevent the spread of epidemics are successful only if the targeted populations subscribe to the recommendations of health authorities. However, because compulsory vaccination is hardly conceivable in modern democracies, governments need to convince their populations through efficient and persuasive information campaigns. In the context of the swine-origin A (H1N1) 2009 pandemic, we use an interactive study among the general public in the South of France, with 175 participants, to explore what type of information can induce change in vaccination intentions at both aggregate and individual levels. We find that individual attitudes to vaccination are based on rational appraisal of the situation, and that it is information of a purely scientific nature that has the only significant positive effect on intention to vaccinate.

Contribution of alcohol use disorders to the burden of dementia in France 2008–13: a nationwide retrospective cohort study

BACKGROUND Dementia is a prevalent condition, affecting 5-7% of people aged 60 years and older, and a leading cause of disability in people aged 60 years and older globally. We aimed to examine the association between alcohol use disorders and dementia risk, with an emphasis on early-onset dementia (<65 years). METHODS We analysed a nationwide retrospective cohort of all adult (≥20 years) patients admitted to hospital in metropolitan France between 2008 and 2013. The primary exposure was alcohol use disorders and the main outcome was dementia, both defined by International Classification of Diseases, tenth revision discharge diagnosis codes. Characteristics of early-onset dementia were studied among prevalent cases in 2008-13. Associations of alcohol use disorders and other risk factors with dementia onset were analysed in multivariate Cox models among patients admitted to hospital in 2011-13 with no record of dementia in 2008-10. FINDINGS Of 31 624 156 adults discharged from French hospitals between 2008 and 2013, 1 109 343 were diagnosed with dementia and were included in the analyses. Of the 57 353 (5·2%) cases of early-onset dementia, most were either alcohol-related by definition (22 338 [38·9%]) or had an additional diagnosis of alcohol use disorders (10 115 [17·6%]). Alcohol use disorders were the strongest modifiable risk factor for dementia onset, with an adjusted hazard ratio of 3·34 (95% CI 3·28-3·41) for women and 3·36 (3·31-3·41) for men. Alcohol use disorders remained associated with dementia onset for both sexes (adjusted hazard ratios >1·7) in sensitivity analyses on dementia case definition (including Alzheimers disease) or older study populations. Also, alcohol use disorders were significantly associated with all other risk factors for dementia onset (all p<0·0001). INTERPRETATION Alcohol use disorders were a major risk factor for onset of all types of dementia, and especially early-onset dementia. Thus, screening for heavy drinking should be part of regular medical care, with intervention or treatment being offered when necessary. Additionally, other alcohol policies should be considered to reduce heavy drinking in the general population. FUNDING None.

Universal access to HIV treatment in developing countries: going beyond the misinterpretations of the 'cost-effectiveness' algorithm.

Background:Economic cost-effectiveness analysis (CEA) has been proposed as the appropriate tool to set priorities for resource allocation among available health interventions. Controversy remains about the way CEA should be used in the field of HIV/AIDS. Methods and objectives:This paper reviews the general literature in health economics and public economics about the use of CEA for priority setting in public health, in order better to inform current debates about resource allocation in the fight against HIV/AIDS. Results:Theoretical and practical limitations of CEA do not raise major problems when it is applied to compare alternatives for treating the same medical condition or public health problem. Using CEA to set priorities among different health interventions by ranking them from the lowest to the highest values of their cost per life-year saved is appropriate only under the very restrictive and unrealistic assumptions that all interventions compared are discrete and finite alternatives that cannot vary in terms of size and scale. In order for CEA to inform resource allocation compared across programmes to fight the AIDS epidemic, a pragmatic interpretation of this economic approach, like that proposed by the Commission on Macroeconomics and Health, is better suited. Interventions, like a number of preventive strategies and first-line antiretroviral treatments for HIV, whose marginal costs per additional life-year saved are less than three times the gross domestic product per capita, should be considered cost-effective. Conclusion:Because of their empirical and theoretical limitations, results of CEA should only be one element in priority setting among interventions for HIV/AIDS, which should also be informed by explicit debates about societal and ethical preferences.

Does public opinion influence willingness-to-pay? Evidence from the field

Contingent valuation (CV) surveys have been criticized for assuming that respondents have well-defined preferences. Using an innovative field experiment dealing with a privatized public good, it is shown that respondents are not influenced by public opinion but are positively responsive to scientific information.

Designing the Financial Tools to Promote Universal Access to AIDS Care

We argue that reluctance to invest in drug treatments to fight the AIDS epidemics in developing countries is largely motivated by severe losses occurring from the future albeit uncertain appearance of a curative vaccine. We design a set of securities generating full insurance coverage against such losses, while achieving full risk-sharing with vaccine development agencies. In a General Equilibrium framework, we show that those securities are demanded to improve social welfare in developing countries, to increase current investment in treatments and the provision of public goods. Even though designed for AIDS, those securities can also be applied to other epidemics such as malaria and tuberculosis, as well as any innovative treatment to fight orphan diseases.

If you have the flu symptoms, your asymptomatic spouse may better answer the willingness-to-pay question: Evidence from a double-bounded dichotomous choice model with heterogeneous anchoring

The small sample size of contingent valuation (CV) surveys conducted in patients may have limited the use of the single-bounded (SB) dichotomous choice format which is recommended in environmental economics. In this paper, we explore two ways to increase the statistical efficiency of the SB format: (1) by the inclusion of proxies in addition to patients; (2) by the addition of a follow-up dichotomous question, i.e. the double-bounded (DB) dichotomous choice format. We found that patients (n=223) and spouses (n=64) answering on behalf of the patient had on average a similar willingness-to-pay for earlier alleviation of flu symptoms. However, a patient was significantly more likely to anchor his/her answer on the first bid as compared to a spouse. Finally, our original DB model with shift effect and heterogeneous anchoring reconciled the discrepancies found in willingness-to-pay statistics between SB and DB models in keeping with increased statistical efficiency.

Coordination with communication under oath

We focus on the design of an institutional device aimed to foster coordination through communication. We explore whether the social psychology theory of commitment, implemented via a truth-telling oath, can reduce coordination failure. Using a classic coordination game, we ask all players to sign voluntarily a truth-telling oath before playing the game with cheap talk communication. Three results emerge with commitment under oath: (1) coordination increased by nearly 50%; (2) senders’ messages were significantly more truthful and actions more efficient, and (3) receivers’ trust of messages increased.

Cognitive ability and the effect of strategic uncertainty

How is one’s cognitive ability related to the way one responds to strategic uncertainty? We address this question by conducting a set of experiments in simple 2 x 2 dominance solvable coordination games. Our experiments involve two main treatments: one in which two human subjects interact, and another in which one human subject interacts with a computer program whose behavior is known. By making the behavior of the computer perfectly predictable, the latter treatment eliminates strategic uncertainty. We find that subjects with higher cognitive ability are more sensitive to strategic uncertainty than those with lower cognitive ability.