Research Interests

  • Social Finance
  • Behavioral Finance
  • Experimental Economics
  • Happiness
  • Millionaires


Millionaires are more generous in dictator games than any other group studied in the literature. Yet, millionaires reduce their generosity in a bargaining context (ultimatum game). For fund raisers, it is therefore important to tap into the giving mindset of the wealthy and prevent an exchange focus like: "You give, you get". 
  • "Buying Time Promotes Happiness", Proceedings of the National Academy of Sciences (with Ashley Whillans, Elizabeth Dunn, Rene Bekkers and Michael Norton) 
How should individuals spend their money to maximize their life satisfaction? Across the United States, Canada, Denmark and the Netherlands, we find that spending money to buy time increases life satisfaction. Outsourcing tasks such as house cleaning, cooking and doing groceries reduce feelings of stress. Yet, surprisingly, almost half of the Dutch millionaires do not buy time.
  • “How Do Millionaires Spend Their Time?” (with Ashley Whillans, Rene Bekkers and Michael Norton), submitted
​Using large samples of millionaires and the general population, we show that millionaires spend their time in a surprisingly similar way as the general population. For example, millionaires spend the same amount of time as the general population cooking, shopping, and eating – and even spend more time on household chores. However, while millionaires and non-millionaires also spend the same amount of time engaging in leisure activities, a critical difference emerged: the wealthy engage in more active leisure (e.g., exercising and volunteering) and less passive leisure (e.g., watching TV and relaxing). Moreover, the extent to which wealthy individuals engage in greater active leisure helps to explain the gap in life satisfaction between millionaires and the general population.
  • "How Do the Rich Think About Redistribution?" (with Alain Cohn, Lasse Jessen and Marko Klasjna)
People have different fairness views, ranging from egalitarian to fully accepting inequality. The distribution of fairness ideals in a society has important implications for political and economic outcomes. Here, we examine redistributive preferences of the rich, as they typically hold high-ranking positions in organizations and politics, and compare their preferences with those of the general population. To this end, we conducted large scale experiments with millionaires and the general population of the United States, in which participants could redistribute money between two workers. Our study shows that millionaires in the US are substantially more tolerant towards inequality than the general population. In particular, we find that one third of the millionaires refuse to redistribute at all, even when the source of inequality is luck as opposed to hard work. 

Sustainable Finance Social preferences are the most important driver for investors to hold socially responsible mutual funds. Many investors accept lower expected returns on socially responsible investments and are willing to pay higher management fees. Providers of socially responsible investments benefit from a focus on the societal impact of responsible investments rather than focusing too much on financial performance.

The extent to which investors at socially responsible banks can identify with their socially responsible investments is an important driver for allocations to socially responsible banks. Return expectations and risk preferences also play a role, but are less important. Providers of socially responsible investments can benefit from creating strong social connections with their clients.

Financial Decision Making

We investigate what triggers individuals to inform themselves about their pension situation. Correct insights into the personal pension situation are important, because even in the Netherlands, where our study took place, one third of pension fund participants are at risk of inadequate pension savings. We find that financial incentives increase retirement information search by 52%. The cost-benefit analysis shows that financial incentives are cost-effective: only $4.21 for informing one additional pension fund beneficiary. In contrast, all our social norms treatments are ineffective. For some social norms treatments, significantly fewer people informed themselves about their personal retirement situation than in the control group. We present a recently developed experimental method to estimate individuals’ time and risk preferences and test it for its suitability in the pension context. We directly compare the approach typically used in the literature, using incentivized experiments with small stakes and short horizons, to more realistic hypothetical long run scenarios with larger stakes. We show that using long run high stakes decision situations can be effective for pension funds interested in estimating risk and time preferences of their clients.
  • "Testosterone and Overconfidence of Investment Managers" (with Pim van Vliet) submitted
​We measured the testosterone levels of professional investment managers who manage about 100 billion euro in assets. We find that testosterone is unrelated to the ability of investment managers to complete a calculation task. Yet, we find a significant relation between testosterone and overconfidence. Investment managers with a high level of testosterone are substantially more likely to believe they outperform their peers than justified by the actual performance data.
  • "Lets Invite the Women: Gender Diversity Reduces Overconfidence in Pairs" (with Tobias Ruof)
We show that gender composition of pairs matters for information processing. Male-only teams suffer from asymmetric belief updating, by responding much stronger to positive feedback than to negative feedback. In contrast, mixed-gender pairs and female-only pairs update their beliefs in a symmetric way. The results inform the debate on gender diversity in companies and universities.

Philanthropy Reports

Joint projects with financial institutions

Robeco abn amro tridos bank asn bank deutsche bank loyalis

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