Research Interests

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

Sustainable Finance

Our research indicates that higher fees for sustainable investments are not due to investors’ social preferences, but rather to their low financial literacy. This finding suggests that investors may not fully understand the impact of these fees on their overall returns, and may benefit from greater education and transparency in the investment industry. Differences in financial literacy across countries explain why investors in Germany and the Netherlands tend to be more fee-sensitive than those in France, Poland, and Spain.

American Finance Association 2024 (Texas)

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In both the United States and Europe, we find that financial advisors charge sustainable investors higher fees than conventional investors. Our experiments with 415 financial advisors suggest that this is not due to any additional effort or costs associated with sustainable investing. Instead, we found evidence of price discrimination, with sustainable investors – especially those with lower financial literacy – being charged the highest fees. These findings have important implications for investors and regulators.

Western Finance Association 2023 (San Francisco)

Pre-registration at AEA RCT Registry

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The United Nations Sustainable Development Goals (SDGs) have created societal and political pressure for pension funds to address sustainable investing. We run two field surveys (n=1,669 and n=3,186) with a pension fund that grants its members a real vote on its sustainable-investment policy. Two thirds of participants are willing to expand the fund’s engagement with companies based on selected SDGs, even when they expect engagement to hurt the financial performance. The support remains strong after the fund implemented the choice. A key reason is participants’ strong social preferences.

Pre-registration at OSF:

Yale-RFS Conference on Real and Private-Value Assets

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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.

Behavioral Finance

Many investors tend to hold on to losing stocks for too long while selling winners too quickly. This behavior, known as the disposition effect, has been the subject of study in the context of a large and recent sample of Dutch retail investors. The results of our research suggest that investors tend to become overconfident after selling stocks at a profit. Specifically, we found that investors learn about their abilities based on their successful sales, which can lead to overconfidence. Our findings are consistent with a model that explains this behavior, and we also demonstrate the causal effect of this phenomenon in an experiment.

Western Finance Association 2022 (Portland) SFS Cavalcade North America 2022 (Chapel Hill)

  • Investor Memory (with Katrin Gödker and Peiran Jiao), Revise and Resubmit at The Review of Financial Studies

Investors have selective memories of prior outcomes, remembering the good ones and forgetting the bad ones. This negatively affects their future investment decisions.

American Finance Association 2020 (San Diego)

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Financial incentives in the form of a lottery increase retirement information search, whereby raffling a few large prizes are more effective than raffling the same amount in the form of many small prizes. However, financial incentives do not improve pension knowledge or savings behavior three weeks after our intervention. Peer information has no effect altogether.

Pre-registration at the AEA RCT Registry:

More than 1400 papers suggest that sex hormones around birth affect later-life decisions, relying on 2D-4D digit ratios as proxy. We are the first to use neo-natal sex hormones from umbilical cord blood and 2D-4D ratios and find no relation with economic preferences like risk preferences, competitiveness and social preferences. We use a large sample from the Raine study, a well-studied cohort in Western Australia.

Pre-registration at OSF

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.


Wealthy individuals have a disproportionately large influence on the income distribution in society through politics and the corporate world. We show that even in the absence of self-interested motives to oppose redistribution, the wealthy may favor policies that further expand the gap between richer and poorer individuals because of their higher tolerance for inequality. Particularly individuals who experienced upward social mobility accept more inequality than those born into wealth.

Previous work suggested that wealthy individuals behave more unethically than less wealthy individuals. Specifically, drivers of expensive cars would be more likely to violate traffic laws than drivers of cheaper cars. We conducted several large-scale replications and find that drivers of expensive and cheap cars are equally likely to violate traffic laws.

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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 HappinessProceedings of the National Academy of Sciences, 2017 (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 (exercising, volunteering, socializing) instead of passive leisure (watching TV), you can be almost as happy as the wealthy.

Pre-registration at the OSF:

Charity Effectiveness

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  • The effects of music education on children’s non-cognitive skills

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Philanthropy Reports

Joint projects with financial institutions