Research Interests

  • Millionaires
  • Philanthropy
  • Sustainable Finance
  • Behavioral Finance
  • Experimental Economics
  • Happiness


Wealthy individuals have a large influence on the income distribution in society through politics and the corporate world. We show that wealthy Americans are less supportive of redistribution than the general population. This gap in attitudes is explained by differences in preferences for inequality rather than beliefs about inequality. Our findings raise the possibility that wealthy individuals contribute to the persistent income inequality in the U.S. 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. What can you learn from the happiness of millionaires? Millionaires rate their life satisfaction with an 8.1 compared to 7.5 for the general population. Yet, it is not the money itself that makes them happy, but the way they spend their time. Thirty minutes per day makes the difference. If you spend half an hour more on active leisure (excercising, volunteering, socializing) instead of passive leisure (watching TV), you can be almost as happy as the wealthy.
- ​Pre-registration at the OSF:
  • The Joy of Giving: Evidence From a Matching Experiment With Millionaires and the General Population" (with Rene Bekkers, Ashley Whillans and Michael Norton). AEA 2019, Atlanta
- Pre-registration at OSF:​

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.
Covered by Harvard Law School Forum

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.

Do people put their pension savings on the table to promote sustainability? We answer this question in a large-scale field experiment (n = 3,256). The pension fund in our study gave its members a real vote for more or less sustainable investments. We find that 66.7% of the participants favor to invest their pension savings in a more sustainable manner. Even among participants who expect lower financial returns on sustainable investments, a majority votes for more sustainable investments in their pension plan.
- Pre-registration at OSF:

Financial Decision Making

  • "Investor Memory" (with Katrin Godker and Peiran Jiao), AFA 2020 San Diego
Investors have selective memories of prior outcomes, remembering the good ones and forgetting the bad ones. This negatively affects their future investment decisions. Financial incentives increase retirement information search and improve pension knowledge three weeks after our intervention. Financial incentives in the form of lotteries are cost-effective: only $1.43 for informing one additional pension fund beneficiary. A few large lottery prizes are more effective than many small lottery prizes. Incentives work equally effectively when used repeatedly compared to a one time use.
- Pre-registration at the AEA RCT Registry:​ We develop an experimental method to estimate individuals’ time and risk preferences tailored to long-term decision making, like pension savings decisions. We directly compare our approach to low stakes incentivized experiments with short horizons, typically used in the literature. 
  • "Testosterone and Overconfidence of Investment Managers" (with Pim van Vliet) 
​We measured the testosterone levels of professional investment managers who manage about 100 billion euro of assets. 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.

Charity Effectiveness

  • ​Social norms and attitudes: Implicit and explicit attitudes towards menstruating girls in Bangladesh (with Eleonora Nilessen and Lidwien Sol)
- Pre-registration at OSF:​

Philanthropy Reports

Joint projects with financial institutions

Robeco abn amro tridos bank asn bank deutsche bank loyalis

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