Publications:
Making and Breaking Promises: On the Voluntary Public Goods Provision under Cost Uncertainty (with Andreas Lange)
Forthcoming in Journal of Economic Behavior and Organization (JEBO) 245, 2026: 107471; https://doi.org/10.1016/j.jebo.2026.107471
The private solution trap in collective action problems across 34 nations (with Eugene Malthouse and CDMCL co-authors)
The Proceedings of the National Academy of Sciences (PNAS) ; https://doi.org/10.1073/pnas.2504632123
The benefits of digital travel information for informal transport: Insights from app users in Cochabamba, Bolivia (with Aljoscha Minnich and Marc Hasselwander)
Journal of Transport Geography ; https://doi.org/10.1016/j.jtrangeo.2026.104574
Working Papers:
People are often motivated to act in a way that sends a favourable signal about their character. This paper proposes a separation of signalling into its direct and indirect components: an observed behaviour can influence a person's image directly when the behaviour itself is image-relevant, and it can influence a person's image indirectly by changing people's beliefs about an unobserved, image-relevant behaviour. In an experiment on charitable giving, we show that individuals engage in indirect signalling to make an ``altruistic bluff'': donors engage in an image-irrelevant behaviour (donating to many charities) to change observers' beliefs about an unobserved, image-relevant behaviour (donating large amounts). This bluff works, as it leads observers to form beliefs that are positively biased.
Status: R&R at Experimental Economics
Promoting cooperation between different groups remains one of society’s biggest challenges. We examine whether such intergroup cooperation can be fostered through observation by in-group leaders, using a lab-in-the-field experiment in Papua New Guinea. The effect of in-group observation is not clear ex ante, as individuals may both want to show themselves as cooperative (‘cooperation motivation’) and show that they prioritize their own group, for example, by only cooperating with members of their own group and not with others (‘favoritism motivation’). We find that the cooperation motivation is stronger: Observation by the in-group leader increases the share of people who cooperate with members of other communities from 17 percent to 70 percent, thereby eliminating the in-group bias in cooperation. We relate this to a shared understanding among participants that intergroup cooperation is socially desirable. Our findings suggest that policymakers, communities, and organizations may leverage in-group observation to improve intergroup cooperation.
Status: submitted
A good neighbor - a found treasure: On the voluntary public good provision in overlapping neighborhoods (Draft available upon request) (with Andreas Lange and Lorenzo Romero)
This paper investigates cooperation in a spatial public goods game with overlapping neighborhoods. Inspired by the public discourse on mixed vs. segregated neighborhoods, we investigate the role of varying spatial allocations of rich and poor for the voluntary provision of public goods. The spatial network structure of public goods investments allows for more nuanced investigations of behavioral motives. We find that participants mainly invest in their own neighborhood, yet that investment patterns respond to concerns of inequality and reciprocity. The spatial clustering of endowments is found to affect inequality. In networks where rich and poor are clustered, we observe that it is the rich located at the border who trigger the redistribution to the poor cluster, thereby reducing inequality between, but also generating inequality within the cluster.
Status: submitted