It's not how you play the game, it's winning that matters: an experimental investigation of asymmetric contests

This paper reports an experimental test of asymmetric Tullock contests. Both the simultaneous-move and sequential-move frameworks are considered. The introduction of asymmetries in the contest function generates experimental behavior qualitatively consistent with the theoretical predictions. However, especially in the simultaneous-move framework, average bidding levels are in excess of the risk-neutral predictions. We conjecture that the reason behind this behavior lies in subjects attaching positive utility to victory in the contest.Laboratory experiments, contests, asymmetries

Social identity, group composition and public good provision: an experimental study

Social fragmentation has been identified as a potential cause for the under-provision of public goods in developing nations, as well as in urban communities in developed countries such as the U.S. We study the effect of social fragmentation on public good provision using laboratory experiments. We create two artificial social groups in the lab and we assign subjects belonging to both groups to a public good game. The treatment variable is the relative size of each social group, which is a proxy for social fragmentation. We find that while higher social fragmentation leads to lower public good provision, this effect is short-lived. Furthermore, social homogeneity does not lead to higher levels of contributions.Social Identity, Public Goods, Social Fragmentation, Experiments.

The effect of social fragmentation on public good provision : an experimental study

publication-status: Publishedtypes: ArticleNOTICE: this is the author’s version of a work that was accepted for publication in Journal of Behavioral and Experimental Economics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Behavioral and Experimental Economics, vol. 53, pp. 1-9 doi:10.1016/j.socec.2014.07.002This version originally published in University of Exeter Economics Department Discussion Papers Series as paper number 12/07We study the role of social identity in determining the impact of social fragmentation on public good provision using laboratory experiments. We find that as long as there is some degree of social fragmentation, increasing it leads to lower public good provision by majority group members. This is mainly because the share of those in the majority group who contribute fully to the public good diminishes with social fragmentation, while the share of free-riders is unchanged. This suggests social identity preferences drive our result, as opposed to self-interest. Importantly, we find no difference in contribution between homogeneous and maximally-fragmented treatments, reinforcing our finding that majority groups contribute most in the presence of some diversity.Economic and Social Research Counci

Endogenous cartel formation: experimental evidence

PublishedArticleNOTICE: this is the author’s version of a work that was accepted for publication in Economics Letters. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Economics Letters, Volume 125, Issue 2, November 2014, Pages 223–225. doi:10.1016/j.econlet.2014.09.014This version previously issued as DICE Discussion Paper, No. 159 by Düsseldorf Institute for Competition EconomicsIn a Bertrand-oligopoly experiment, firms choose whether or not to engage in cartel-like communication and, if so, they may get fined by a cartel authority. We find that the four-firm industries form cartels more often than the duopolies because they gain less from a hysteresis effect after cartel disruption

An integrated formal methods tool-chain and its application to verifying a file system model

Tool interoperability as a mean to achieve integration is among the main goals of the international Grand Challenge initiative. In the context of the Verifiable file system mini-challenge put forward by Rajeev Joshi and Gerard Holzmann, this paper focuses on the integration of different formal methods and tools in modelling and verifying an abstract file system inspired by the Intel (R) Flash File System Core. We combine high-level manual specification and proofs with current state of the art mechanical verification tools into a tool-chain which involves Alloy, VDM++ and HOL. The use of (pointfree) relation modelling provides the glue which binds these tools together.Mondrian Project funded by the Portuguese NSF under contract PTDC/EIA-CCO/108302/200

Alloy meets the algebra of programming: a case study

Relational algebra offers to software engineering the same degree of conciseness and calculational power as linear algebra in other engineering disciplines. Binary relations play the role of matrices with similar emphasis on multiplication and transposition. This matches with Alloy’s lemma “everything is a relation” and with the relational basis of the Algebra of Programming (AoP). Altogether, it provides a simple and coherent approach to checking and calculating programs from abstract models. In this paper, we put Alloy and the Algebra of Programming together in a case study originating from the Verifiable File System mini-challenge put forward by Joshi and Holzmann: verifying the refinement of an abstract file store model into a journaled (FLASH) data model catering to wear leveling and recovery from power loss. Our approach relies on diagrams to graphically express typed assertions. It interweaves model checking (in Alloy) with calculational proofs in a way which offers the best of both worlds. This provides ample evidence of the positive impact in software verification of Alloy’s focus on relations, complemented by induction-free proofs about data structures such as stores and lists.Fundação para a Ciência e a Tecnologia (FCT

An experiment on the causes of bank run contagions

NOTICE: this is the author’s version of a work that was accepted for publication in European Economic Review. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in European Economic Review, vol. 72, pp. 39-51. DOI 10.1016/j.euroecorev.2014.09.003This version originally published in University of Exeter Economics Department Discussion Paper Series, Paper No. 12/06To understand the mechanisms behind bank run contagions, we conduct bank run experiments in a modified Diamond–Dybvig setup with two banks (Left and Right). The banks׳ liquidity levels are either linked or independent. Left Bank depositors see their bank׳s liquidity level before deciding. Right Bank depositors only see Left Bank withdrawals before deciding. We find that Left Bank depositors׳ actions significantly affect Right Bank depositors׳ behavior, even when liquidities are independent. Furthermore, a panic may be a one-way street: an increase in Left Bank withdrawals can cause a panic run on the Right Bank, but a decrease does not calm depositors

Religious fragmentation, social identity and cooperation: Evidence from a artefactual field experiment in India

We study the role of village-level religious fragmentation on intra- and inter-group cooperation in India. We report on data on two-player Prisoners Dilemma and Stag Hunt experiments played by 516 Hindu and Muslim participants in rural India. Our treatments are the identity of the two players and the degree of village-level religious heterogeneity. In religiously-heterogeneous villages, cooperation rates in the Prisoners Dilemma are higher when subjects play with another in-group member for both Hindus and Muslims, but to a much lesser extent in the Stag Hunt game. This suggests that positive in-group biases operate primarily on the willingness to achieve socially efficient outcomes, rather than through beliefs about the actions by one’s counterpart. Interestingly, cooperation rates among people of the same religion are significantly lower in homogeneous villages than in fragmented villages in both games. This is likely because a sense of group identity is only meaningful in the presence of an outgroup. This, together with little evidence for out-group prejudice in either game, means religious diversity is beneficial

The wisdom of crowds: predicting a weather and climate-related event

types: ArticleArticle published in open-access journal, Judgment and Decision Making, vol. 8(2), pp. 91-105Environmental uncertainty is at the core of much of human activity, ranging from daily decisions by individuals to long-term policy planning by governments. Yet, there is little quantitative evidence on the ability of non-expert individuals or populations to forecast climate-related events. Here we report on data from a 90-year old prediction game on a climate related event in Alaska: the Nenana Ice Classic (NIC). Participants in this contest guess to the nearest minute when the ice covering the Tanana River will break, signaling the start of spring. Previous research indicates a strong correlation between the ice breakup dates and regional weather conditions. We study betting decisions between 1955 and 2009. We find the betting distribution closely predicts the outcome of the contest. We also find a significant correlation between regional temperatures as well as past ice breakups and betting behavior, suggesting that participants incorporate both climate and historical information into their decision-making