Individual Risk Attitudes: Measurement, Determinants and Behavioral Consequences

This paper studies risk attitudes using a large representative survey and a complementaryexperiment conducted with a representative subject pool in subjects’ homes. Using aquestion asking people about their willingness to take risks “in general”, we find thatgender, age, height, and parental background have an economically significant impacton willingness to take risks. The experiment confirms the behavioral validity of thismeasure, using paid lottery choices. Turning to other question about risk attitudesin specific contexts, we find similar results on the determinants of risk attitudes, andalso shed light on the deeper question of stability of risk attitudes across contexts. Weconduct a horse race of the ability of different measures to explain risky behaviorssuch as holdings stocks, occupational choice, and smoking. The question about risktakingin general generates the best all-around predictor of risky behavior. (JEL codes:D0, D1, D80, D81, C91, C93, J16, J24, I1).education, training and the labour market;

Individual Risk Attitudes: New Evidence from a Large, Representative, Experimentally-Validated Survey

This paper presents new evidence on the distribution of risk attitudes in the population, using a novel set of survey questions and a representative sample of roughly 22,000 individuals living in Germany. Using a question that asks about willingness to take risks on an 11-point scale, we find evidence of heterogeneity across individuals, and show that willingness to take risks is negatively related to age and being female, and positively related to height and parental education. We test the behavioral relevance of this survey measure by conducting a complementary field experiment, based on a representative sample of 450 subjects, and find that the measure is a good predictor of actual risk-taking behavior. We then use a more standard lottery question to measure risk preference, and find similar results regarding heterogeneity and determinants of risk preferences. The lottery question makes it possible to estimate the coefficient of relative risk aversion for each individual in the sample. Using five questions about willingness to take risks in specific domains - car driving, financial matters, sports and leisure, career, and health - the paper also studies the impact of context on risk attitudes, finding a strong but imperfect correlation across contexts. Using data on a collection of risky behaviors from different contexts, including traffic offenses, portfolio choice, smoking, occupational choice, participation in sports, and migration, the paper compares the predictive power of all of the risk measures. Strikingly, the general risk question predicts all behaviors whereas the standard lottery measure does not. The best overall predictor for any specific behavior is typically the corresponding context-specific measure. These findings call into the question the current preoccupation with lottery measures of risk preference, and point to variation in risk perceptions as an understudied determinant of risky behavior.Risk preferences; Preference stability; Experimental validation; Field experiment; SOEP; Gender differences; Age; Height; Subjective well-being

Individual Risk Attitudes: Measurement, Determinants and Behavioral Consequences

This paper studies risk attitudes using a large representative survey and a complementary experiment conducted with a representative subject pool in subjects'' homes. Using a question asking people about their willingness to take risks "in general", we find that gender, age, height, and parental background have an economically significant impact on willingness to take risks. The experiment confirms the behavioral validity of this measure, using paid lottery choices. Turning to other questions about risk attitudes in specific contexts, we find similar results on the determinants of risk attitudes, and also shed light on the deeper question of stability of risk attitudes across contexts. We conduct a horse race of the ability of different measures to explain risky behaviors such as holdings stocks, occupational choice, and smoking. The question about risk-taking in general generates the best all-around predictor of risky behavior.Economics ;

Hsp70 and Hsp110 chaperones promote early steps of proteasome assembly

Whereas assembly of the 20S proteasome core particle (CP) in prokaryotes apparently occurs spontaneously, the efficiency of this process in eukaryotes relies on the dedicated assembly chaperones Ump1, Pba1-Pba2, and Pba3-Pba4. For mammals, it was reported that CP assembly initiates with formation of a complete alpha-ring that functions as a template for beta subunit incorporation. By contrast, we were not able to detect a ring composed only of a complete set of alpha subunits in S. cerevisiae. Instead, we found that the CP subunits alpha 1, alpha 2, and alpha 4 each form independent small complexes. Purification of such complexes containing alpha 4 revealed the presence of chaperones of the Hsp70/Ssa and Hsp110/Sse families. Consistently, certain small complexes containing alpha 1, alpha 2, and alpha 4 were not formed in strains lacking these chaperones. Deletion of the SSE1 gene in combination with deletions of PRE9 (alpha 3), PBA3, or UMP1 genes resulted in severe synthetic growth defects, high levels of ubiquitin-conjugates, and an accumulation of distinct small complexes with alpha subunits. Our study shows that Hsp70 and Hsp110 chaperones cooperate to promote the folding of individual alpha subunits and/or their assembly with other CP subunits, Ump1, and Pba1-Pba4 in subsequent steps.info:eu-repo/semantics/publishedVersio

Proteasome assembly from 15S precursors involves major conformational changes and recycling of the Pba1-Pba2 chaperone

The chaperones Ump1 and Pba1-Pba2 promote efficient biogenesis of 20S proteasome core particles from its subunits via 15S intermediates containing alpha and beta subunits, except beta7. Here we elucidate the structural role of these chaperones in late steps of core particle biogenesis using biochemical, electron microscopy, cross-linking and mass spectrometry analyses. In 15S precursor complexes, Ump1 is largely unstructured, lining the inner cavity of the complex along the interface between alpha and beta subunits. The alpha and beta subunits form loosely packed rings with a wider alpha ring opening than in the 20S core particle, allowing for the Pba1-Pba2 heterodimer to be partially embedded in the central alpha ring cavity. During biogenesis, the heterodimer is expelled from the alpha ring by a restructuring event that organizes the beta ring and leads to tightening of the alpha ring opening. In this way, the Pba1-Pba2 chaperone is recycled for a new round of proteasome assembly

The impact of an hematocrit of 20% during normothermic cardiopulmonary bypass for elective low risk coronary artery bypass graft surgery on oxygen delivery and clinical outcome – a randomized controlled study [ISRCTN35655335]

INTRODUCTION: Cardiopulmonary bypass (CPB) induces hemodilutional anemia, which frequently requires the transfusion of blood products. The objective of this study was to evaluate oxygen delivery and consumption and clinical outcome in low risk patients who were allocated to an hematocrit (Hct) of 20% versus 25% during normothermic CPB for elective coronary artery bypass graft (CABG) surgery. METHODS: This study was a prospective, randomized and controlled trial. Patients were subjected to normothermic CPB (35 to 36°C) and were observed until discharge from the intensive care unit (ICU). Outcome measures were calculated whole body oxygen delivery, oxygen consumption and clinical outcome. A nonparametric multivariate analysis of variance for repeated measurements and small sample sizes was performed. RESULTS: In a total of 54 patients (25% Hct, n = 28; 20% Hct, n = 26), calculated oxygen delivery (p = 0.11), oxygen consumption (p = 0.06) and blood lactate (p = 0.60) were not significantly different between groups. Clinical outcomes were not different between groups. CONCLUSION: These data indicate that an Hct of 20% during normothermic CPB maintained calculated whole body oxygen delivery above a critical level after elective CABG surgery in low risk patients. The question of whether a transfusion trigger in excess of 20% Hct during normothermic CPB is still supported requires a larger prospective and randomized trial