Accommodating stake effects under prospect theory

One of the stylized facts underlying prospect theory is a four-fold pattern of risk preferences. People have been shown to be risk seeking for small probability gains and large probability losses, while being risk averse for large probability gains and small probability losses. Another fourfold pattern of risk preferences over outcomes, postulated by Harry Markowitz in 1952, has received much less attention and is currently not integrated into prospect theory. In two experiments, we show that risk preferences may change over outcomes. While we find people to be risk seeking for small outcomes, this turns to risk neutrality and later risk aversion as stakes increase. We then show how a one-parameter logarithmic utility function fits such stake effects significantly better under prospect theory than the power or exponential functions mostly used when fitting prospect theory models. We further investigate the extent to which the use of ill-suited functional forms to represent utility may result in violations of prospect theory, and whether such violations disappear when using logarithmic utility

Using social and behavioural science to support COVID-19 pandemic response

The COVID-19 pandemic represents a massive global health crisis. Because the crisis requires large-scale behaviour change and places significant psychological burdens on individuals, insights from the social and behavioural sciences can be used to help align human behavior with the recommendations of epidemiologists and public health experts. Here we discuss evidence from a selection of research topics relevant to pandemics, including work on navigating threats, social and cultural influences on behaviour, science communication, moral decision-making, leadership, and stress and coping. In each section, we note the nature and quality of prior research, including uncertainty and unsettled issues. We identify several insights for effective response to the COVID-19 pandemic, and also highlight important gaps researchers should move quickly to fill in the coming weeks and months

ABCs of principal-agent interactions: Accurate predictions, biased processes, and contrasts between working and delegating

We experimentally investigate people’s evaluations of incentive pay contracts and people’s predictions of others’ evaluations of incentive pay contracts. We emphasize that the construction of evaluations and predictions often includes two substeps, involving likelihood judgment and likelihood weighting. Predictors appear to be biased at both substeps but in opposing directions. Accurate overall predictions thus sometimes reflect two errors that are of the same magnitude and thereby offset. Moreover, predictions can become more inaccurate if one step is debiased but the other is left untouched. Importantly, principals deciding whether to delegate a task are susceptible to just one of the biases. Delegation assessments are thus often flawed, reflecting a single error that is not offset

Recurrent unintended pregnancies among young unmarried women serving in the Israeli military

Abstract Background Unintended pregnancy is a major public health problem with known risk factors, however, little is known about the prevalence of variables associated with recurrent unintended pregnancy (RUP) among young, unmarried women. Methods A retrospective cohort study of unmarried women aged 18–21 serving in the Israeli military between 2013 and 2015. Multivariable logistic regression analysis was used to examine associations between RUP and women’s education, IQ, immigration status, country of origin, socioeconomic status and history of psychiatric illness. Results Of 129,638 women drafted by the Israeli military during the study period, 1720 women with unintended pregnancies had a follow up period of at least a year. Three hundred and eighty-nine of them had RUP (22.6%). Multivariable models comparing women with no unintended pregnancies and women with RUP revealed that RUP was more common among (adjusted relative risk; 95% confidence interval) women who had not graduated from high school (6.9; 4.99–9.55), who had low (90–99) IQ scores (3.9; 2.88–5.39) those reporting Africa as the country of origin (2.5; 1.37–4.59) and those from a lower socioeconomic neighborhood (1.6; 1.18–2.05). Multivariate regression modeling comparing women with single unintended pregnancies and women with RUPs showed that recurrent unintended pregnancy was more common among women who had not graduated from high school (3.2; 2.04–4.84) and those who had a low (90–99) IQ score (1.9; 1.32–2.61). Conclusion Rate of RUP is high among women serving in the Israeli military. These women have unique epidemiological characteristics. This may serve in identifying populations at high risk and thus may enable policy maker to offer at least to this population Long-Acting Reversible Contraception (LARC) methods. We encourage policy makers to consider the provision of LARC methods to all servicewomen who had an unintended pregnancy

Prolonged operative time of repeat cesarean is a risk marker for post-operative maternal complications

Abstract Background Repeat cesarean delivery (CD) accounts for approximately 15% of all annual deliveries in the US with an estimated 656,250 operations per year. We aimed to study whether prolonged operative time (OT; skin incision to closure) is a risk marker for post-operative maternal complications among women undergoing repeat CD. Methods We conducted a cross-sectional retrospective study in a single tertiary center including all women who underwent repeat CD but excluding those with cesarean hysterectomy. Prolonged OT was defined as duration of CD longer than the 90th percentile duration on record for each specific surgeon in order to correct for technique differences between surgeons. Bi-variate analysis was used to study the association of prolonged OT with each one of the following maternal complications: post-operative blood transfusion, prolonged maternal hospitalization (defined as hospitalization duration longer than 1 week post-CD), infection necessitating antibiotics, re-laparotomy within 7 days post-CD, and re-admission within 42 days post-CD. A multivariate regression analysis was performed controlling for maternal age, ethnicity, parity, number of fetus, gestational age at delivery, trial of labor after cesarean, anesthesia, and number of previous CDs. The adjusted odd ratio was calculated for each complication independently and for a composite adverse maternal outcome defined as any one of the above. Results A total of 6507 repeat CDs were included; prolonged OT was highly associated (P value < 0.000) with: post-operative blood transfusion (4.4% vs. 1.5%), prolonged hospitalization (8.4% vs. 4.0%), infection necessitating antibiotics (2% vs. 1%), and readmission (1.8% vs. 0.8%) when compared to control. The composite adverse maternal outcome was also associated with prolonged OT (20.2% vs. 11.2%, p < 0.000). These correlations remained statistically significant in the multivariate regression analysis when controlling for confounders. Conclusions Among women undergoing repeat CD, prolonged OT (reflecting CD duration greater than 90th percentile for the specific surgeon) is a risk marker for post-operative maternal complications