From contemplating politics to doing health research

I think there are two best things about my job. One is the gratification and the sense of fulfilment I derive from teaching students. And the second thing is that you really have a lot of flexibility and the opportunity to do a lot of research visits. I spent a lot of time in Los Angeles to collaborate with colleagues over there. I also spent 2.5 years in Hong Kong. These are both professionally as well as personally, wonderful experiences.

I don't think I had a very clear idea of what I wanted to become as a child. Some years I thought about becoming a politician, some years I thought about becoming a literature critic and some time I thought about opening my own hotel. But when I was doing my master's thesis, I realised I enjoyed the research. I enjoyed the thinking part, the data analysis part and writing down my research ideas. Around the same time, one of my professors asked me whether I would be interested in doing a PhD. At first I was doubtful, I didn't even really know what it involved, doing a PhD. But then I also got in touch with a professor in health economics and that made me very excited, because he sort of sketched that I could be applying econometrics and the things that I had learned during my study on a socially relevant problem, namely health and the inequalities in health by socioeconomic status. This is what made me really excited to start an academic career and do a PhD.

Inspiration

My inspiration for doing the type of research I do now mainly started when I was visiting Los Angeles in 2009. This was one of my first research visits, and I was staying in Venice Beach. What I saw there, really fascinated me. If you walk on the boulevard of Venice Beach you see people being offered pizza slices for one dollar and very big cans of Coke, and a lot of people are overweight and from lower socio-economic groups. I took my bike and I cycled a few blocks away from there to go to the Wholefoods market, which is an organic, very expensive supermarket. And there you see the complete opposite. There are banners that say: “Your health starts here”. Rich people walk around over there with their own personal trainer, only drinking organic juices and eating fresh vegetables. This very big contrast, only a few blocks away from each other is what really fascinated me. Why do some people behave so healthily? Why don't other people care at all about their health? And how is this related to income, education, occupation? This reallyfascinated me and this is how my research in health behaviour started.

If you live in poverty, if you have debt and if the only thing you can think about is how to send your kids to school or how to pay the bills, then your health is not the first thing you worry about. So, I think that a simple economic framework already gives you some idea about why certain people behave healthier than others. But in my view, for understanding health behaviour, economic theory is not enough. I mean, just modelling health behaviour from a rational point of view doesn’t do the job. What we need at a minimum in this context, is the psychological insight of Daniel Kahneman – a Nobel laureate – of two systems. Basically, people have system 1 which is more focused on the present, the more intuitive system. And on the other hand there's system 2, as Kahneman calls it, and this is the more deliberative system, the one who plans ahead and thinks about the future. We can think about health behaviour as a constant negotiation between this system 1 and system 2. And this involves self-control. Because if you want to follow through on your intentions, this requires quite a bit of self-control.

Current endeavours

So, what we are trying to do now in the context of the Smarter Choices for Better Health initiative is by combining the rational theory of health behaviour with the idea of two systems, the role of self-control and the role of temptations. And I think this may help to understand not just the intentions that people form but also why their actions sometimes deviate from their intentions. We are about to start a field experiment with patients of the Erasmus MC where we combine economic stakes (give them monetary incentives) with psychological skills (train self-control, planning and commitment skills) to help people realize their intentions for physical activity.

Another large project I’m currently working is on how genetic and environmental factors jointly shape human capital (i.e., education and health). Only recently large-scale datasets with both genetic data and environmental factors became available. Our preliminary findings suggest that both genetic and environmental factors matter a great deal in driving education and health, and they do not operate independently. For example, children who randomly inherited genetic endowments for educational attainment benefit more from parental time investments when young. I think this research is fascinating, because it allows to fundamentally improve understanding of how nature and nurture jointly shape human life chances, it is consistent with economic theories that suggest dynamic complementarity between endowments and investments. And more generally, it shows how strongly things like education, health and income are influenced by factors beyond one’s control (genes, parental investments, family background), which has ethical implications for redistribution and fairness in society.

A lesson for students

As a student, you should realise that you're privileged to study what you want and where you want. So, I think you should take the opportunity of being able to study seriously, but never take yourself too seriously.