Publications
(with Lionel Page and John Wooders) Accepted at Quantitative Economics. [Press]
Abstract: Mixed strategy Nash equilibrium is the cornerstone of our understanding of strategic situations that require decision makers to be unpredictable. Using data from nearly half a million serves over 3000 tennis matches, and data on player rankings from the ATP and WTA, we examine whether the behavior of professional tennis players is consistent with equilibrium. We find that win rates conform remarkably closely to the theory for men, but conform somewhat less neatly for women. We show that the behavior in the field of more highly ranked (i.e., better) players conforms more closely to theory.
(with Stephanie A. Heger and Robert Slonim) Journal of Economic Behavior & Organization, (2020).
Abstract: We challenge a commonly used assumption in the literature on social preferences and show that this assumption leads to significantly biased estimates of the social preference parameter. Using Monte Carlo simulations, we demonstrate that the literature's common restrictions on the curvature of the decision-makers utility function can dramatically bias the altruism parameter. We show that this is particularly problematic when comparing altruism between groups with well-documented differences in risk aversion or diminishing marginal utility, i.e., men versus women, giving motivated by pure versus warm glow motives, and wealthy versus poor.
(with Lionel Page) The Economic Journal, (2019).
Best paper award at the 2015 PhD Conference in Economics and Business, University of Queensland, Australia (500 AUD). [Link]Abstract: We study how agents adapt their behaviour to variations of incentives in dynamic contests. We investigate a real dynamic contest with large stakes: professional tennis matches. Situations where balls bounce very close to the court's lines are used as the setting of a quasi-experiment providing random variations in winning probability. We find evidence of a momentum effect for men whereby winning a point has a positive causal impact on the probability to win the next one. This behaviour is compatible with a reaction to the asymmetry of incentives between leaders and followers. We do not find momentum for women.
(with Lionel Page ) Review of Economics and Statistics, (2019).[Press]
Abstract: We provide evidence of a violation of the informativeness principle whereby lucky successes are overly rewarded. We isolate a quasi-experimental situation where the success of an agent is as good as random. To do so, we use high quality data on football (soccer) matches and select shots on goal which landed on the goal posts. Using non scoring shots, taken from a similar location on the pitch, as counterfactuals to scoring shots, we estimate the causal effect of a lucky success (goal) on the evaluation of the player's performance. We find clear evidence that luck is overly influencing managers' decisions and evaluators' ratings. Our results suggest that this phenomenon is likely to be widespread in economic organizations.
(with Lionel Page) Journal of Economic Behavior & Organization, (2018).
Abstract: We study the existence of a psychological momentum commonly believed to exist in a real world contest: the effect of scoring just before half-time in association football (soccer). Using high quality data on football matches, we isolate a quasi-experimental situation to identify the effect of scoring on later performance. We carefully select shots toward the goal, taken from a similar location on the pitch, which landed on the goal posts. Using the non-goal shots as conterfactuals to the scoring shots, we estimate the causal effect of scoring at different times in the first half. We do not find any evidence of an effect of scoring before half-time. This result contributes to the debate on whether psychological momentum exists in contests.
(with Jeffrey C. Ely and Lionel Page) Journal of Economic Psychology, (2017).
Abstract: We investigate whether expert players with high incentives are able to optimally determine their degree of risk taking in contest. We use a large dataset on tennis matches and look at players’ risk taking on first and second serves. We isolate a specific situation, let serves, where second serves and first serves occur in a way which is as good as random. This creates the setting of a quasi-experiment which we can use to study players’ serving strategies on first and second serves in comparable serving situations. We find that players, both men and women, are able to adopt serving strategies which meet the requirements of optimality arising from simple assumptions about risk-return trade-offs in serves.
(with Lionel Page) American Economic Review: Papers and Proceedings, (2015). [Press release][Blog]
Abstract: In most collective actions, individuals' incentives are not perfectly aligned with the goals of the group/team they are part of. We investigate how individual specific incentives affect both individuals and team leaders' strategies in a natural setting. We use a discontinuity in individual rewards in batsmen scoring in cricket to identify the causal effect of such incentives on behavior. We find that batsmen react to the presence of individual-specific incentives by adopting strategies that may be suboptimal at the team level. More surprisingly, we also find that team captains react to these individual incentives by adopting suboptimal strategies at the team level, which may bring large benefits to the individual players. These results suggest a complex interplay of individual and team incentives which we conjecture may arise in repeated team interactions.
Blomstedt, P., Gauriot, R., Viitala, N., Reinikainen, T. and Corander, J. Journal of Chemometrics, (2014). [Video]
Abstract: Statistical comparison of oil samples is an integral part of oil spill identification, which deals with the process of linking an oil spill with its source of origin. In current practice, a frequentist hypothesis test is often used to evaluate evidence in support of a match between a spill and a source sample. As frequentist tests are only able to evaluate evidence against a hypothesis but not in support of it, we argue that this leads to unsound statistical reasoning. Moreover, currently only verbal conclusions on a very coarse scale can be made about the match between two samples, whereas a finer quantitative assessment would often be preferred. To address these issues, we propose a Bayesian predictive approach for evaluating the similarity between the chemical compositions of two oil samples. We derive the underlying statistical model from some basic assumptions on modeling assays in analytical chemistry, and to further facilitate and improve numerical evaluations, we develop analytical expressions for the key element of Bayesian inference for this model. The approach is illustrated with both simulated and real data and is shown to have appealing properties in comparison with both standard frequentist and Bayesian approaches.
Gauriot, R., Gunaratnam, L., Moroni, R., Reinikainen, T. and Corander, J. Journal of Forensic Sciences, (2013).
Abstract: The discharging of a gun results in the formation of extremely small particles known as gunshot residues (GSR). These may be deposited on the skin and clothing of the shooter, on other persons present, and on nearby items or surfaces. Several factors and their complex interactions affect the number of detectable GSR particles, which can deeply influence the conclusions drawn from likelihood ratios or posterior probabilities for prosecution hypotheses of interest. We present Bayesian network models for casework examples and demonstrate that probabilistic quantification of GSR evidence can be very sensitive to the assumptions concerning the model structure, prior probabilities, and the likelihood components. This finding has considerable implications for the use of statistical quantification of GSR evidence in the legal process.
