This study compares discounting for money and health in a field study. We applied the direct method, which measures discounting independent of utility, in a representative French sample, interviewed at home by professional interviewers. We found more discounting for money than for health. The median discount rates (6.5% for money and 2.2% for health) were close to market interest rates, suggesting that at the aggregate level the direct method solves the puzzle of unrealistically high discount rates typically observed in applied economics. Constant discounting fitted the data better than the hyperbolic discounting models that we considered. The substantial individual heterogeneity in discounting was correlated with age and occupation.

To achieve the full benefits of vaccination, it is key to understand the underlying causes of low vaccination by researching the barriers to vaccination at a local level. This systematic literature review aims to identify the reasons given by community members for the non-vaccination and under-vaccination of children and adolescents in sub-Saharan Africa. PubMed, Web of Science, PsycINFO, African Index Medicus, and African Journals Online databases were searched to identify articles published between 2010 and 2020. A total of 37 articles were included. As 17 studies did not report the reasons for non-vaccination and under-vaccination separately, we considered these two outcomes as “incomplete vaccination”. The most common reasons for incomplete vaccination were related to caregiver’s time constraints, lack of knowledge regarding vaccination, the unavailability of vaccines/personnel in healthcare facilities, missed opportunities for vaccination, caregiver’s fear of minor side effects, poor access to vaccination services, and caregiver’s vaccination beliefs.

Prenatal screening for Down syndrome (DS) is widely performed at 11 to 14 weeks of gestation by using a combination of maternal age, measurements of fetal nuchal translucency by ultrasonography, and maternal serum concentrations of free human chorionic gonadotropin and plasma protein A.¹ Various cutoffs of risk have been chosen to offer invasive testing (IT) as a second step, usually between 1 in 100 and 1 in 300.¹ More recently, noninvasive prenatal testing (NIPT) using cell-free DNA circulating in maternal plasma has emerged as an intermediate step within a conditional screening algorithm, as the positive predictive value of combined screening is around 1 in 16 for DS.^2-7 In contrast with IT, which involves a risk of miscarriage but provides full information on all possible chromosomal abnormalities, NIPT carries no risk of miscarriage but only provides information on the targeted abnormalities and only in terms of very high likelihood of their presence or absence. Indeed, the accuracy of cell-free-DNA to detect DS is around 99% with a 0.1% false-positive rate, and IT is carried out to confirm a positive result.⁸ As a result, NIPT therefore involves both a risky, although almost certain, component about targeted abnormalities together with an uncertain component about nontargeted abnormalities. In addition to the well-known attractiveness of certainty in decision making (also known as the certainty effect^9,10), presenting information involving both risky and uncertain components is known to trigger ambiguity aversion^11,12 as a result of a preference for known risks (probabilities) over unknown risks.¹³ Decision making between IT and NIPT could therefore be driven by aversion toward ambiguous information as much as by IT-related pregnancy loss risk aversion.