On Thursday 9 February 2023, Jacob Dalgaard Christensen had his dissertation with the thesis "Risk, reproducibility, and reproduction : Essays on scholar’s analytic decisions and consumers' product purchases". Professor Erik Wengström from Lund University was the opponent. Big congratulations!
"This thesis investigates how evolutionary biology theories can be used to better understand consumer behavior. The first paper lays the groundwork for the methodologies used throughout the thesis. Here, the focus is on the (ab-)use of p-values and how easy it is to find a false-positive research result under different common circumstances. The second paper investigates what happens with the willingness to engage in risky choices when people have a low level of blood glucose. The third and fourth papers focus on conspicuous consumption and examine the circumstances that induce people to purchase prestigious products. The empirical studies have in common the idea that the respective choices involved in each paper are embedded in an evolutionary process. In the first paper, we find that obtaining a false positive result is easy, especially when there is no pre-registration of the hypothesis or no correction of p-values for multiple hypothesis testing. In some important cases, pre-registration alone is not sufficient to overcome the problem of inflated false positives. Applying these insights to an empirical case and using theoretical arguments from evolutionary biology, the second paper uses cross-validation and a meta-analysis to show that people with low levels of blood glucose show a higher willingness to pay for risky food items, whereas this is not the case for non-food products. The third paper shows through two studies that conspicuous consumption is particularly prevalent among single men. Building on these findings, the fourth paper shows, through a newly constructed uncertainty index, that increased uncertainty amplifies people’s propensity to engage in conspicuous consumption. Overall, this thesis adds to the literature on false-positive findings and illuminates how social scientists can reach a deeper understanding of human behavior by adopting an evolutionary lens."
false positive results; budget rule; conspicuous consumption; natural language processing; evolutionary biology; blood glucose; relationship status