About me
“No man is an island entire of itself,” wrote the English poet John Donne in 1624. The thought that people (and firms) do not make choices in isolation but operate within a social context sparked my research agenda. During my PhD at the University of Groningen (1999-2004), I started to examine the connection between social interactions and economic outcomes. This topic still is my prime motivation for doing research, together with a deeply felt need to bring theory to data. Whenever possible, I implement field experiments – randomized controlled trials (RCTs) in which participants make choices in their normal day-to-day environment – to establish causality. However, oftentimes this is not possible because either the question at hand or the context does not lend itself for an experimental approach. In such cases, I am more than happy to combine happenstance or survey data with econometric techniques.
My early work on social interactions includes studies on the role of anonymity in charitable giving, and on peer effects in consumption and behavior between high-school teens and neighbors. Peter Kooreman, who was (together with Bert Schoonbeek) my PhD supervisor, has had a key role as mentor and collaborator in launching these lines of work. Peter Kooreman, Peter Kuhn and Arie Kapteyn and I ran the large and long-running study on the impact that winning the lottery has on the consumption patterns of their non-winning next door neighbors. This study was conceived in 2001 and published in 2011.
Research stays at the University of Wisconsin (2002, with Steven Durlauf and William Brock) and Tufts University (2003, with Yannis Ioannides) have been very formative. With Yannis, I worked on a theoretical research program that looked into the role of social networks in inequality in labor market outcomes, just in the period that social network theory – traditionally a topic in sociology – gained traction in economics.
After my PhD, I moved to the Industrial Organization group at the University of Amsterdam. In this period (2004-2013), I gained experience with laboratory experiments due to the presence of the world class CREED-laboratory and colleagues like Jeroen Hinloopen, Sander Onderstal and Arthur Schram. This led to studies examining the impact of leniency programs in fighthing collusive practices and the optimal mechanism for charities to raise money.
The combination of these components – social and strategic interactions, innovative data collection using laboratory and field RCTs – is also a key ingredient in my second line of research in which I examine how spatial or network components impact competition. My interest is in topics such as market pricing and strategic interactions between firms, including coordination between firms in the form of collusive practices. In 2007, NWO awarded me a VENI grant for a project on firms’ locational choice and competition on networks. Among other things, I used this grant to construct a large panel data set with daily retail fuel prices of more than 90% of all petrol stations in the Netherlands, covering the years 2005-2011. Analysis of this data with Marco Haan and Pim Heijnen provided important quantitative insights on the extent to which (forced) ownership changes, and technological progress in the form of automation, foster competition. The team has also developed a so-called variance screen to flag possible collusive practices by identifying spatial clustering in price trends, an approach that is useful to, and has been picked up by antitrust authorities.
In 2013, I returned to the University of Groningen where I am involved in running the GrEELab Experimental Economics Laboratory with my colleague Noemi Peter. In 2016, the signature area Markets & Sustainability (M&S) was launched. M&S is an interdisciplinary research network where researchers from economics, marketing and operations work together on sustainability issues. M&S is connected to the university-wide theme of Sustainable Society.
Private Life
