Unique bid auctions: Equilibrium solutions and experimental evidence

Two types of auction were introduced on the Internet a few years ago and have rapidly been gaining widespread popularity. In both auctions, players compete for an exogenously determined prize by independently choosing an integer in some finite and common strategy space specified by the auctioneer. In the unique lowest (highest) bid auction, the winner of the prize is the player who submits the lowest (highest) bid, provided that it is unique. We construct the symmetric mixed-strategy equilibrium solutions to the two auctions, and then test them in a sequence of experiments that vary the number of bidders and size of the strategy space. Our results show that the aggregate bids, but only a minority of the individual bidders, are accounted for quite accurately by the equilibrium solutions.

Quantal Response Equilibrium vs. Cognitive Hierarchies : An Analysis of Initial Responses in an Asymmetric All-Pay\nAuction Experiment

Predicting initial responses to novel strategic situations has been a challenge in game theory. People are not as sophisticated as players assumed by solution concepts in game theory, and their initial play has a tendency to systematically deviate from equilibrium. Several behavioral models of games have been proposed to bridge a gap between initial behavior and equilibrium play. This paper fits two one-parameter behavioral models, a quantal response equilibrium（QRE） and a cognitive hierarchy（CH） model, into the first-round data of the experiment conducted by Otsubo （2013）. Estimation results show that the QRE accounts better for deviations from Nash equilibrium play than the CH model

The Effect of Role Origin on Bidding Behavior in an Asymmetric All-Pay Auction:An Experiment

This paper reports the results of an experiment concerning whether different origins of bidder role affect bidding behavior in the two-person all-pay auction in which ties are broken in favor of one role (strong bidder) over the other (weak bidder). Two role allocation procedures are compared. In the first one, the roles are allocated at random. In the second one, the roles are allocated based on their performance in a simple real-effort task. The data provided no evidence toconfirm the effect of role origin on bidding behavior in the current asymmetric all-pay auction

Unique bid auctions: Equilibrium solutions and experimental evidence

Two types of auction were introduced on the Internet a few years ago and have rapidly been gaining widespread popularity. In both auctions, players compete for an exogenously determined prize by independently choosing an integer in some finite and common strategy space specified by the auctioneer. In the unique lowest (highest) bid auction, the winner of the prize is the player who submits the lowest (highest) bid, provided that it is unique. We construct the symmetric mixed-strategy equilibrium solutions to the two auctions, and then test them in a sequence of experiments that vary the number of bidders and size of the strategy space. Our results show that the aggregate bids, but only a minority of the individual bidders, are accounted for quite accurately by the equilibrium solutions.unique bid auctions; equilibrium analysis; experiment

Learning (Not) To Yield: An Experimental Study of Evolving Ultimatum Game Behavior

Whether behavior converges toward rational play or fair play in repeated ultimatum games depends on which player yields first. If responders concede first by accepting low offers, proposers would not need to learn to offer more, and play would converge toward unequal sharing. By the same token, if proposers learn fast that low offers are doomed to be rejected and adjust their offers accordingly, pressure would be lifted from responders to learn to accept such offers. Play would converge toward equal sharing. Here we tested the hypothesis that it is regret-both material and strategic-which determines how players modify their behavior. We conducted a repeated ultimatum game experiment with random strangers, in which one treatment does and another does not provide population feedback in addition to informing players about their own outcome. Our results show that regret is a good predictor of the dynamics of play. Specifically, we will turn to the dynamics that unfold when players make repeated decisions in the ultimatum game with randomly changing opponents, and when they learn not only about their own outcome in the previous round but also find out how the population on average has adapted to previous results (path dependence).Ultimatum bargaining game, Reputation, Regret, Learning, Experiment

Unique bid auctions: Equilibrium solutions and experimental evidence

Two types of auction were introduced on the Internet a few years ago and have rapidly been gaining widespread popularity. In both auctions, players compete for an exogenously determined prize by independently choosing an integer in some finite and common strategy space specified by the auctioneer. In the unique lowest (highest) bid auction, the winner of the prize is the player who submits the lowest (highest) bid, provided that it is unique. We construct the symmetric mixed-strategy equilibrium solutions to the two auctions, and then test them in a sequence of experiments that vary the number of bidders and size of the strategy space. Our results show that the aggregate bids, but only a minority of the individual bidders, are accounted for quite accurately by the equilibrium solutions

Genetic and clinical landscape of breast cancers with germline BRCA1/2 variants

遺伝性乳癌の遺伝学的・臨床学的特徴を解明 --BRCA1/2 変異乳癌は両アレルの不活化の有無により異なった特徴を持つ--. 京都大学プレスリリース. 2020-10-26.The genetic and clinical characteristics of breast tumors with germline variants, including their association with biallelic inactivation through loss-of-heterozygosity (LOH) and second somatic mutations, remain elusive. We analyzed germline variants of 11 breast cancer susceptibility genes for 1, 995 Japanese breast cancer patients, and identified 101 (5.1%) pathogenic variants, including 62 BRCA2 and 15 BRCA1 mutations. Genetic analysis of 64 BRCA1/2-mutated tumors including TCGA dataset tumors, revealed an association of biallelic inactivation with more extensive deletions, copy neutral LOH, gain with LOH and younger onset. Strikingly, TP53 and RB1 mutations were frequently observed in BRCA1- (94%) and BRCA2- (9.7%) mutated tumors with biallelic inactivation. Inactivation of TP53 and RB1 together with BRCA1 and BRCA2, respectively, involved LOH of chromosomes 17 and 13. Notably, BRCA1/2 tumors without biallelic inactivation were indistinguishable from those without germline variants. Our study highlights the heterogeneity and unique clonal selection pattern in breast cancers with germline variants

Dynamic Volunteer's Dilemmas, Unique Bid Auctions, and Discrete Bottleneck Games: Theory and Experiments

The main theme of my dissertation is the analysis of several interactive decision making situations with multiple decision makers whose interests do not fully coincide. Non-cooperative game theory is invoked to carry on this analysis.The first chapter describes an experimental study of volunteer's dilemmas that evolve over time. Only a single volunteer is required for the public good to be provided. Because volunteering is costly, each prefers that some other players bear the full costs of volunteering. Reflecting on the observation that in many naturally occurring social dilemmas it is beneficial to volunteer earlier than later, I assume that the payoff to the volunteer and the (higher) payoff to each of the non-volunteers decrease monotonically over time. I derive symmetric and asymmetric subgame perfect equilibria. The experimental results provide little support to asymmetric equilibria in which only a single subject volunteers immediately. In comparison to the symmetric subgame perfect equilibrium, they show that subjects volunteer, on average, earlier than predicted.The second chapter explores a new type of online auction, called the unique bid auction, that has recently emerged on the Internet and gained widespread popularity in many countries. In a sharp contrast to traditional auctions, the winner in this class of auctions is the bidder who submits the lowest (highest) unique bid; all ties are discarded. I propose an algorithm to numerically compute the symmetric mixed-strategy Nash equilibrium solution and then conduct a series of experiments to assess the predictive power of the equilibrium solution. The experimental results show that the solution accounts quite well for the subjects' bidding behavior on the aggregate level, but not on the individual level.The last chapter proposes a discrete version of William Vickrey's model of traffic congestion on a single road with a single bottleneck. In my model, both the strategy space and number of commuters are finite. An algorithm similar to the one used in the second chapter is proposed to numerically calculate the symmetric mixed-strategy Nash equilibrium. The discrete model is then compared with the original continuous model of Vickrey in terms of the equilibrium solution and its implications