Game Theory

The main theme running through most of my economic research is that of coordination problems and how to resolve them. Coordination problems are ubiquitous, but our understanding of them remains  limited. So, this is a truly exciting and fulfilling area to work in. Under the broad theme of coordination problems, my work is spread over a couple of inter-related topics. Here’s a brief overview of the main things I have worked, with links to relevant working papers and recent articles. 

Threshold public goods

Many goods can be modelled as threshold public goods. Despite this, relatively little attention has been paid to threshold public good games in the research literature. That leaves a worryingly large gap in our understanding that I am keen to try and close. I find threshold public good games fascinating because we see the ‘free-riding incentive’ common to all public good games, combined with a ‘coordination problem’ of how to split the cost of providing the good. I also believe that a better understanding of these games can help unlock important secrets to solving general coordination problems. The three main themes running through my current work (in collaboration with Federica Alberti and Anna Stepanova) are: (i) to provide a theoretical framework with which to make sense of the disparate experimental results existing in the literature, (ii) to better understand the role of focal points and norms of coordination, (iii) to evaluate the consequences of institutions like leadership. Our latest work includes:

Cartwright, E. & A. Stepanova, (2017). 'Efficiency in a forced contribution threshold public good game,' International Journal of Game Theory.

Albert, F. & E. Cartwright, (2016). 'Full agreement and the provision of threshold public goods', Public Choice, 166: 205-233.

Cartwright, E. & A. Stepanova, (2015). 'The consequences of a refund in threshold public good games,' Economics Letters 134: 29-33.

Cartwright, E. & F. Alberti, (2015). 'Does the endowment of contributors make a difference in threshold public good games,' Finanz Archiv 71: 216-239. 

Alberti, F., E. Cartwright & A. Stepanova, (2013). 'Explaining success rates at providing threshold public goods: An approach based on impulse balance theory,' SSRN.

Social norms

My PhD was focussed on social norms, and I continue to work on the issue today. This primarily reflects my belief that norms are an incredibly important determinant of economic behaviour. And one that economists don’t treat anywhere near seriously enough. Under the broad topic of social norms I am working on various things. The one constant is the application of game theory to provide novel ways to model and think about social norms.

Conformity and correlated equilibrium. Most game theoretic models of conformity equate conformity with playing the same strategy. This, however, is inadequate because conformity typically involves people following roles that allow different people to perform different actions. What we need is a way to reconcile ‘playing the same strategy’ with ‘performing different actions’. In ongoing work with Myrna Wooders we argue that correlated equilibrium is the key to achieving this. See, for example, our paper: 

Cartwright, E., and M. Wooders (2014) 'Correlated equilibrium, conformity and stereotyping in social groups', Journal of Public Economic Theory 16: 743-766.

Prejudice and stereotyping. As far as I know there are no game theoretic models of prejudice. Prejudice is also largely absent from economic models. That doesn’t seem good enough! In work with Myrna Wooders, initially funded by a Nuffield Small Research Grant, we are trying to build a game theoretic model of prejudice that can be meaningfully applied in economic models. Of particularly interest is to understand the feedback loops between prejudice and discrimination. 

Cartwright, E. and M. Wooders (2020) 'Own experience bias in evaluating the effort of others', Journal of Economic Behavior and Organisation.

Signalling and norms. Douglas Bernheim’s seminal paper on conformity (published in the Journal of Political Economy 1994) convinced me that signalling games provide a fantastic way to model social norms and conformity. I have, therefore, worked a fair bit on this topic. For example, with Amrish Patel looked at the potential for appropriately set category thresholds to increase giving to charity.

Cartwright, E. & A. Patel, (2013). 'How Category Reporting Can Improve fundraising', Journal of Economic Behavior and Organization, 87: 73–90.

Patel, A. and E. Cartwright (2012) 'Naïve beliefs and the multiplicity of socialnorms', Journal of Institutional and Theoretical Economics, 168: 280-289.

Cartwright, E. and A. Patel (2010) 'Public goods, social norms, and naive beliefs', Journal of Public Economic Theory 12: 199-223.

Leadership

My interest in leadership began while working with psychologist Mark van Vugt. Since, I have come to view leadership as a fascinating issue and one of fundamental importance for understanding group behaviour. My initial work with Mark, funded by an ESRC Small Research Grant, focused on the questions such as: Who becomes leader and why? Is leadership based on personality or strategic incentives? Do we get dominant or servant leaders? While continuing to work on such questions I have also become interested in the consequences of leadership. For example, in work with Amrish Patel, we are looking at the role of leadership in public good games.

Cartwright, E. (2015) 'Strategic delay and information cascades,' Journal of Economics 114: 53-74.

Cartwright, E. and D. Lovett (2014) 'Conditional cooperation and the marginal per-capita return in public good games', Games 5: 234-256.

Cartwright, E., J. Gillet, and M. van Vugt, (2013) 'Leadership in a weak-link game', Economic Inquiry, 51: 2028-2043.

Gillet, J., E. Cartwright and M. van Vugt (2011) 'Selfish or servant leadership: Evolutionary predictions on leadership personalities in coordination games', Personality and Individual Differences, 51: 231-236.

Cartwright, E. and A. Patel (2010) 'Imitation and the incentive to contribute early in a sequential public good game', Journal of Public Economic Theory 12: 691-708.

Coordination games

My general interest in coordination games has led me to work on various other projects. For example, recent work looks at the stag-hunt game and weak link or minimum effort game. Of particular interest is how choices can spread through networks. In my PhD I also got interested in ex-post stability and continue to work on that today. My main goal is to study ex-post stability in coordination games.

Cartwright, E. and T. Singh (2018) 'Observation and contagion effects in cooperation: An experimental investigation', Journal of Behavioral and Experimental Economics. 

Cartwright, E. (2014) 'Imitation and coordination in small world networks', Intelligent Systems in Accounting, Finance and Management, 21: 71-90.