The role of psychological and physiological factors in decision making under risk and in a dilemma

We study the difference in the result of two different risk elicitation methods by linking estimates of risk attitudes to gender, age, personality traits, a decision in a dilemma situation, and physiological states measured by heart rate variability (HRV). Our results indicate that differences between the methods can partly be explained by gender, but not by personality traits. Furthermore, HRV is linked to risktaking in the experiment for at least one of the methods, indicating that more stressed individuals display more risk aversion. Finally, we and that risk attitudes are not predictive of the ability to decide in a dilemma, but personality traits are. Surprisingly, there is also no apparent relationship between the physiological state during the dilemma situation and the ability to make a decision.

Gender and other determinants of trust and reciprocity in an experimental labour market amongst Chinese students

Due to economic and demographic changes highly educated women play an important role on the Chinese labour market. Gender has been shown to be an important characteristic that influences behaviour in economic experiments, as have, to a lesser degree, academic major, age and income. We provide a study looking at trust and reciprocity and their determinants in a labour market laboratory experiment. Our experimental data is based on two games, the Gift Exchange Game (GEG) and a variant of this game (the Wage Promising Game, WPG) where the employer's wage offer is non-binding and the employer can choose the wage freely after observing the workers effort. We and that women are less trusting and reciprocal than men in the GEG while this cannot be found in the WPG. Letting participants play the GEG and the WPG, allows us to disentangle reciprocal and risk attitudes. While in the employer role, it seems to be that risk attitude is the main factor, this is not confirmed analysing decisions in the worker role.

How distributional preferences shape incentives on (experimental) markets for credence goods

Credence goods markets suffer from inefficiencies caused by superior information of sellers about the surplus-maximizing quality. While standard theory predicts that equal mark-up prices solve the credence goods problem if customers can verify the quality received, experimental evidence indicates the opposite. We identify a lack of robustness of institutional design with respect to heterogeneity in distributional preferences as a possible cause and design new experiments that allow for parsimonious identification of sellers’ distributional types. Our results indicate that less than a fourth of the subjects behave according to standard theory’s assumption, the rest behaving either in line with non-standard selfish or in accordance with non-trivial other-regarding preferences. We discuss consequences of our findings for institutional design and agent selection.

Contracting for infrastructure projects as credence goods

Large infrastructure projects are a major responsibility of urban and regional governments, who usually lack expertise to fully specify the demanded projects. Contractors, typically experts on such projects due to experience with similar projects elsewhere, advise of the needed design in their bids. Producing the right design is nevertheless costly. We model such infrastructure projects taking into account their credence goods feature and the costly design effort they require and examine the performance of commonly used contracting methods. We show that when building costs are homogeneous and public information, multi-stage competitive bidding involving shortlisting of two contractors and contingent compensation of both contractors on design efforts outperforms sequential search and the traditional Design-and-Build approach. If building costs are private information of the contractors and are revealed to them after design cost is sunk, sequential search may be superior to the other two methods.

Exit polls, turnout, and bandwagon voting : evidence from a natural experiment

We exploit a voting reform in France to estimate the causal effect of exit poll information on turnout and bandwagon voting. Before the change in legislation, individuals in some French overseas territories voted after the election result had already been made public via exit poll information from mainland France. We estimate that knowing the exit poll information decreases voter turnout by about 12 percentage points. Our study is the first clean empirical design outside of the laboratory to demonstrate the effect of such knowledge on voter turnout. Furthermore, we find that exit poll information significantly increases bandwagon voting; that is, voters who choose to turn out are more likely to vote for the expected winner.

Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis

Variation in body iron is associated with or causes diseases, including anaemia and iron overload. Here, we analyse genetic association data on biochemical markers of iron status from 11 European-population studies, with replication in eight additional cohorts (total up to 48,972 subjects). We find 11 genome-wide-significant (P<5 × 10−8) loci, some including known iron-related genes (​HFE, ​SLC40A1, ​TF, ​TFR2, ​TFRC, ​TMPRSS6) and others novel (​ABO, ​ARNTL, ​FADS2, ​NAT2, ​TEX14). SNPs at ​ARNTL, ​TF, and ​TFR2 affect iron markers in ​HFE C282Y homozygotes at risk for hemochromatosis. There is substantial overlap between our iron loci and loci affecting erythrocyte and lipid phenotypes. These results will facilitate investigation of the roles of iron in disease.