.com
This paper, which is joint with Jonathan Stieglitz and Karine Van Der Straeten, is forthcoming in Evolutionary Human Science. A non-copy-edited version is here.
This paper, which is joint with Emmanuelle Auriol, Diego Delissaint, Maleke Fourati and Pepita Miguel-Florensa, is now published in Economics of Transition and Institutional Change. You can download the paper here.
This paper, which is joint with Emmanuelle Auriol, Julie Lassébie, Amma Panin and Eva Raiber, is now published at the Quarterly Journal of Economics. It’s available on open access here:
https://academic.oup.com/qje/article/135/4/1799/5861944
We started this project back in 2015.
Here are some pictures of very colorful Ghanaian coffins:
This paper, the result of our project with Jeanne Bovet, Eva Raiber, Weiwei Ren and Charlotte Wang, has come out in the British Journal of Psychology (2018). DOI:10.1111/bjop.12319
You can find the final paper here:
https://onlinelibrary.wiley.com/doi/10.1111/bjop.12319
You can find a near-final prepublication version here.
Abstract:
Both parents and offspring have evolved mating preferences that enable them to select mates and children‐in‐law to maximize their inclusive fitness. The theory of parent–offspring conflict predicts that preferences for potential mates may differ between parents and offspring: individuals are expected to value biological quality more in their own mates than in their offspring’s mates and to value investment potential more in their offspring’s mates than in their own mates. We tested this hypothesis in China using a naturalistic ‘marriage market’ where parents actively search for marital partners for their offspring. Parents gather at a public park to advertise the characteristics of their adult children, looking for a potential son or daughter‐in‐law. We presented 589 parents and young adults from the city of Kunming (Yunnan, China) with hypothetical mating candidates varying in their levels of income (proxy for investment potential) and physical attractiveness (proxy for biological quality). We found some evidence of a parent–offspring conflict over mate choice, but only in the case of daughters, who evaluated physical attractiveness as more important than parents. We also found an effect of the mating candidate’s sex, as physical attractiveness was deemed more valuable in a female potential mate by parents and offspring alike.
Just published in Archives de Sciences Sociales des Religions 175 (2016), pp. 201-219.
The pdf is here.
This paper, joint with Alice Mesnard, is forthcoming in the Journal of Demographic Economics, and the uncorrected proof is available here.
Abstract:
This paper models how migration both influences and responds to differences in disease prevalence between cities and shows how the possibility of migration away from high-prevalence areas affects long-run steady state disease prevalence. We develop a dynamic framework where migration responds to the prevalence of disease, to the costs of migration and to the costs of living. The model explores how pressure for migration in response to differing equilibrium levels of disease prevalence generates differences in city characteristics such as land rents. Competition for scarce housing in low-prevalence areas can create segregation, with disease concentrated in high-prevalence “sinks”. We show that policies affecting migration costs affect the steady-state disease prevalence across cities. In particular, migration can reduce steady-state disease incidence in low-prevalence areas while having no impact on prevalence in high-prevalence areas. This suggests that, in some circumstances, public health measures may need to avoid discouraging migration away from high-disease areas.
This article (joint with Pierre Dubois, Olivier de Mouzon and Fiona Scott Morton), has now appeared in the Rand Journal of Economics, and is available under Open Access.
Abstract:
This article quantifies the relationship between market size and innovation in the pharmaceutical industry using improved, and newer, methods and data. We find significant elasticities of innovation to expected market size with a point estimate under our preferred specification of 0.23. This suggests that, on average, $2.5 billion is required in additional revenue to support the invention of one new chemical entity. This magnitude is plausible given recent accounting estimates of the cost of innovation of $800 million to $1 billion per drug, and marginal costs of manufacture and distribution near 50%.
This article, joint with Samuele Centorrino, Elodie Djemai, Astrid Hopfensitz and Manfred Milinski, has now appeared in Adaptive Human Behavior and Physiology, and is available under Open Access.
Abstract:
We develop a theoretical model under which “genuine” or “convincing” smiling is a costly signal that has evolved to induce cooperation in situations requiring mutual trust. Prior to a trust interaction involving a decision by a sender to send money to a recipient, the recipient can emit a signal to induce the sender to trust them. The signal takes the form of a smile that may be perceived as more or less convincing, and that can be made more convincing with the investment of greater effort. Individuals differ in their degree of altruism and in their tendency to display reciprocity. The model generates three testable predictions. First, the perceived quality of the recipient’s smile is increasing in the size of the stake. Secondly, the amount sent by the sender is increasing in the perceived quality of the recipient’s smile. Thirdly, the expected gain to senders from sending money to the recipient is increasing in the perceived quality of the recipient’s smile.
This paper by Samuele Centorrino, Elodie Djemai, Astrid Hopfensitz,Manfred Milinski and me has now appeared in Evolution and Human Behavior.
The link is here:
Abstract:
We test the hypothesis that smiles perceived as honest serve as a signal that has evolved to induce cooperation in situations requiring mutual trust. Potential trustees (84 participants from Toulouse, France) made two video clips averaging around 15
seconds for viewing by potential senders before the latter decided whether to ‘send’ or ‘keep’ a lower stake (4 euro) or higher stake (8 euro). Senders (198 participants from Lyon, France) made trust decisions with respect to the recorded clips. If money was sent to the trustee, stakes were tripled and trustees could decide to keep all, two thirds or one half of the tripled stakes. Clips were further rated concerning the genuineness of the displayed smiles. We observe that smiles rated as more genuine strongly predict judgments about the trustworthiness of trustees, and willingness to send them money. We observe a relation between costs and benefits: smiles from trustees playing for higher stakes are rated as significantly more genuine. Finally, we show that those rated as smiling genuinely return more money on average to senders. An increase of one standard deviation in rating of smile genuineness is associated with an unconditional expected gain of about one dollar and thirty cents to senders in the two trials of the experiment. Potential gains for senders could be significantly increased from taking smiles rated as genuine into account.
Our theoretical paper, entitled “A Model of Smiling as a Costly SIgnal of Cooperation Opportunities”, has now been published, in Adaptive Human Behavior and Physiology, and is available here. Here is the abstract:
We develop a theoretical model under which “genuine” or “convincing” smiling is a costly signal that has evolved to induce cooperation in situations requiring mutual trust. Prior to a trust interaction involving a decision by a sender to send money to a recipient, the recipient can emit a signal to induce the sender to trust them. The signal takes the form of a smile that may be perceived as more or less convincing, and that can be made more convincing with the investment of greater effort. Individuals differ in their degree of altruism and in their tendency to display reciprocity. The model generates three testable predictions. First, the perceived quality of the recipient’s smile is increasing in the size of the stake. Secondly, the amount sent by the sender is increasing in the perceived quality of the recipient’s smile. Thirdly, the expected gain to senders from sending money to the recipient is increasing in the perceived quality of the recipient’s smile.
This paper from Mark Glick, Greg Richards, Margarita Sapozhnikov and me is now published in Review of Industrial Organization, and is available under Open Access here.
Here is the abstract:
This paper investigates whether a search engine’s ordering of algorithmic results has an important effect on website traffic. A website’s ranking on a search engine results page is positively correlated with the clicks that it receives. This could result from the search engine’s accurately predicting the websites relevance to users. Or it could result from users merely clicking on the highest ranked links, regardless of the website’s relevance. Using a unique dataset, we find that a website’s rank, not just its relevance, strongly and significantly affects the likelihood of a click. We also find evidence that rank influences CTRs partly by controlling access to the scarce attention of users, but primarily by substituting the reputational capital of the search engine for the reputation of individual websites.