Agent Failures in All-Pay Auctions

Information sharing decisions in all-pay auctions with correlated types

We introduce the serial contest by building on the desirable properties of two prominent contest games. This family of contest games relies both on relative efforts (as Tullock’s proposal) and on absolute effort differences (as difference-form contests). An additional desirable feature is that the serial contest is homogeneous of degree zero in contestants’ efforts. The family is characterized by a parameter representing how sensitive the outcome is to contestants’ efforts. It encompasses as polar cases the (fair) lottery and the (deterministic) all-pay auction. Equilibria have a close relationship to those of the (deterministic) all-pay auction and important properties of the latter hold for the serial contest, too.

We analyse the all-pay auction with incomplete information and variance-averse bidders. We characterise the symmetric equilibrium for general distributions of valuations and any number of bidders. Variance aversion is a sufficient assumption to predict that high-valuation bidders increase their bids relative to the risk-neutral case while low types decrease their bid. Considering an asymmetric two-player environment with uniform valuations, we show that a more variance-averse type always bids higher than her less variance-averse counterpart. Utilising our analytical bidding functions we discuss all-pay auctions with variance-averse bidders from a designer’s perspective. We extend our basic model to include noisy signals and allow for the possibility of variance-seeking preferences and type-dependent attitudes towards risk. (JEL C7, D7, D81. Keywords: Auctions, Contests, Mean-Variance preferences.)

How to take multiple factors into account when evaluating a Game with a Purpose? How is player behaviour or participation influenced by different incentives? How does player engagement impact their accuracy in solving tasks? In this paper, we present a detailed investigation of multiple factors affecting the evaluation of a GWAP and we show how they impact on the achieved results. We inform our study with the experimental assessment of a GWAP designed to solve a multinomial classification task.

Developing computer-controlled groups to engage in combat, control the use of limited resources, and create units and buildings in real-time strategy (RTS) games is a novel application in game AI. However, tightly controlled online commercial game pose challenges to researchers interested in observing player activities, constructing player strategy models, and developing practical AI technology in them. Instead of setting up new programming environments or building a large amount of agentpsilas decision rules by playerpsilas experience for conducting real-time AI research, the authors use replays of the commercial RTS game StarCraft to evaluate human player behaviors and to construct an intelligent system to learn human-like decisions and behaviors. A case-based reasoning approach was applied for the purpose of training our system to learn and predict player strategies. Our analysis indicates that the proposed system is capable of learning and predicting individual player strategies, and that players provide evidence of their personal characteristics through their building construction order.

Stackelberg games and multiple equilibrium behaviors on networks

Uncertainties in different parameters such as the output power of renewable energy sources, available capacity of generators, or the condition of grid lines in the future, face market players with financial risks in the power system. Futures contracts are used in parallel with the day-ahead electricity markets to protect market players against financial risks of undesirable price fluctuations. Supplying a demand by both futures and day-ahead markets leads to mutual impacts between these two markets. In this paper, a Nash equilibrium approach is introduced to model the interactions between the futures and day-ahead markets. The proposed model includes producers, retailers, and speculators as market players, the uncertainty in the output power of wind farms (WFs), the possibility of the financial settlement of contracts, market players' risk preferences, and transmission system limitations. Using this approach, the optimal strategy of market players in futures and day-ahead markets, the effects of transmission system congestion on the Nash equilibrium of the system, and the role of the financial settlement of contracts in dealing with the uncertainty of WFs' output power and transmission lines capacity are discussed. Eventually, the behavior of speculators and their impacts on the gaming of other market players are evaluated. Simulation results highlight the role of the financial delivery feature in the effective utilization of futures contracts and the behavior of market players.

This article explores the globalization of U.S. Major League Baseball (MLB), measured by the participation of foreign-born players in the sport from 1876 to 2005. Data show that the number of non-native athletes has been increasing since the end of World War II, suggesting that MLB is becoming a more globalized organization. An investigation at regional and country levels reveals that most foreign participants in the 1990s and early 21st century are from Latin America, especially the Dominican Republic. In contrast, most African, European, and Asian countries have shown little sign of participation. This implies that the global reach of MLB is limited. An empirical study of 2005 data suggests that prosperous countries, neighboring countries, or countries having a close political relationship with the U.S. tend to provide more athletes to MLB. In other words, the globalization of MLB is reliant on America’s economic, cultural, and geographic proximity to the rest of the world.

The ninth edition of Stockley's Drug Interactions, in thirty-eight chapters, with a comprehensive index and abbreviations key, continues to build on the editorial team's extensive experience analyzing the literature on drug interactions. The beauty of this work is that it addresses the needs of busy doctors, pharmacists, nurses, and other health care professionals by including a short summary of the interaction. The advice on managing the interaction is discussed separately from the detailed clinical evidence and mechanism information. Stockley's Drug Interactions remains the world's most comprehensive and authoritative reference book on drug interactions. This work contains detailed yet concise information and covers interactions between therapeutic drugs, proprietary medicines, herbal medicines, foods, drinks, pesticides, and drugs of abuse. Containing more than 3,400 entries, this fully referenced tome is based on published sources, provides comprehensive details of the clinical evidence for the interactions under discussion, assesses their clinical importance, and gives clear guidance on how to manage the interaction in practice. This 9th edition includes a wealth of new information: more than 300 new entries; all entries fully revised and revalidated, making them totally up to date; and three new chapters on the interaction of thyroid hormones, urological drugs, nutritional agents, supplements, vitamins, and new drugs launched in the last 2 years, including drugs such as fesoterodine, several monoclonal antibodies, new antidiabetics such as sitagliptin, new antineoplastic such as dasatinib, and new immune suppressants such as temsirolimus. Also, updated information on season flu vaccines and antivirals is newly included, plus all available information on possible interactions with concurrent medication. It is also worth mentioning that this edition includes increased commentary on the involvement of new mechanisms in drug interactions, such as drug transporter proteins, and other genetic factors that affect the ability of individuals to metabolize medicines. As in previous editions, the editors do not include a symbol to rate the severity of an interaction, because it is not always possible to simply assign one rating and one symbol to the discussion of a group of drugs and their risks. Also, each patient is unique and different. Thus, the editors discuss these various risks and differences, where applicable, and allow readers to make the decision on the severity of the interaction with full knowledge of a particular patient. On the other hand, the editors include ratings symbols in other products such as Stockley's Drug Interactions Pocket Companion, where the interaction information is designed to be abridged and summarized in a few lines and where the symbol presents a worst case scenario. In other words, each entry has been assigned a rating symbol to offer guidance to users on the clinical significance of the interaction. These ratings are arrived at using three separate categories: action, severity, and evidence. Action describes whether or not any action needs to be taken to accommodate the interaction. This category ranges from “avoid” to “no action needed.” Severity describes the likely effect of an unmanaged interaction on the patient. This category ranges from “severe” to “nothing expected.” Evidence describes the weight of evidence behind the interaction. This category ranges from “extensive” to “theoretical.” This pocket companion follows the familiar format of the ninth edition and is conveniently sized to fit in one's pocket. Why consult both the wrist-challenging ninth edition tome and the handy pocket edition? Doctors, pharmacists, nurses, and other health care professionals can find ready answers to questions facing them on a day-to-day basis. Answers to such questions could save a life. Are the drugs in question known to interact or is the interaction only theoretical and speculative? If the drugs do interact, how seriously? Are all patients affected or only a few? Is it best to avoid these two drugs altogether or can the interaction be accommodated in some way? What alternative and safer drugs can be used instead? Purchasing the ninth edition and the Pocket Companion, in the Americas only, includes one-year access to Stockley's Online at MedicinesComplete for a grand total of $250.00 and is sometimes referred to as Stockley's Solution. Purchased separately, Pharmaceutical Press charges $819.00. Stockley's Drug Interactions is a tried and trusted tool of value in any academic health sciences library, hospital library, pharmacy, and physician's office, while the pocket companion is worth its weight in gold away from the book shelf.

It is our great pleasure to welcome you to The Third International Conference on Human-Agent Interaction (HAI 2015) in Korea. HAI has grown beyond our expectations in last two years and this year's HAI continues its tradition of being the relevant forum for presentation of research results and experience reports on leading edge issues of Human-Agent Interaction. HAI gathers researchers from fields spanning engineering, computer science, psychology, sociology and cognitive science while covering diverse topics including Human-Virtual/Physical agent interaction, communication and interaction with smart home/smart cars, and modeling of those interactions. The mission of the conference is to share novel quantitative and qualitative research on human and artificial agent interaction and identify new directions for future research and development. HAI gives researchers and practitioners a unique opportunity to share their perspectives with others interested in the various aspects of human-agent interaction. This year HAI has three exciting keynote talks by the world leaders in areas related to human-agent interaction. We encourage participants to attend them. These valuable and insightful talks can and will guide us to a better understanding of various research issues and methods in the field: Designing the Robotic User Experience: Behavior and Appearance by Guy Hoffman (Assistant-Professor, IDC Herzlyia)Understanding Human Internal States: I Know What You Are and What You Think by Soo-Young Lee (Professor, KAIST)The Evolutionary Origins of Human Cognitive Development: Insights from Research on Chimpanzees by Tetsuro Matsuzawa (Professor, Kyoto University) We also have 23 oral presentations, 51 poster presentations and 2 workshops. All of them present latest research results and ideas. Discussion between researchers from all over the world will be exciting.

User-centered design (UCD) commonly requires direct player participation, yet budget limitations or restricted access to users can impede this goal. To address these challenges, this research explores a transformer-based approach coupled with a diffusion process to replicate real player behavior in a 2D side-scrolling action–adventure environment that emphasizes exploration. By collecting an extensive set of gameplay data from real participants in an open-source game, “A Robot Named Fight!”, this study gathered comprehensive state and input information for training. A transformer model was then adapted to generate button-press sequences from encoded game states, while the diffusion mechanism iteratively introduced and removed noise to refine its predictions. The results indicate a high degree of replication of the participant’s actions in contexts similar to the training data, as well as reasonable adaptation to previously unseen scenarios. Observational analysis further confirmed that the model mirrored essential aspects of the user’s style, including navigation strategies, the avoidance of unnecessary combat, and selective obstacle clearance. Despite hardware constraints and reliance on a single observer’s feedback, these findings suggest that a transformer–diffusion methodology can robustly approximate user behavior. This approach holds promise not only for automated playtesting and level design assistance in similar action–adventure games but also for broader domains where simulating user interaction can streamline iterative design and enhance player-centric outcomes.

In a class of symmetric N-person games we consider the behavior, for large N, of the symmetric equilibrium. In the game each player independently chooses one of M alternatives; the payoff is a decreasing function of the number of players choosing the same alternative. Asymptotic approximations for the equilibrium strategy and payoff are obtained. A number of examples are treated in detail. We also consider the maximin strategy of a single player against $N - 1$ minimizing opponents. It is shown, for a certain subclass of payoff functions, that this maximin payoff is asymptotic to the symmetric equilibrium payoff and the maximin strategy is related asymptotically to the symmetric equilibrium strategy.

Arsenic (As) is a naturally occurring ubiquitous element. It is found in the environment in the earth crust and quantities in media such as soil, water, rock and air. It is present in the environment naturally and due to human activities and other industrial processes such as mining and coal-fired power plants. Arsenic has also been used as a pesticide to protect animals, wood, fruit and vegetables from insects. Because of its therapeutic properties, arsenic has also been used as a medicinal agent. The dark side of the medicine was the reputation as an attractive poison Arsenic is mainly transported in the environment by food, except in areas with high levels of arsenic in the drinking water e.g. India, Taiwan and Bangladesh (2004; Singh, Kumar, and Sahu 2007). The outbreak of As was triggered by deep drilled wells and the desire to obtain microorganism-free safety drinking water. Arsenic contamination of drinking-water is a hazard to human health. Because of the toxicities and side effects of arsenic compounds it is known as a major environmental pollutant. The IARC classified arsenic and arsenic compounds as a human carcinogen (Group 1) (2004). But although arsenic compounds have been known and used for centuries, their mechanisms of interaction in humans are not fully elucidated. The paradox of arsenic compounds is that, on the one hand, they are considered extremely dangerous for human health with acute and chronic adverse health effects. Long-term arsenic exposure can lead to several types of cancer. The exposure to As has been associated also with non-carcinogenic effects e.g. such diabetes and cardiovascular diseases. On the other hand arsenic compounds are regarded as potential drugs against cancer and ranging from the use as poisons to applications in semiconductors and pesticides. Especially the discovery of organoarsenicals for the treatment of hematological malignancies and solid tumor has awakened interest.

Methods of symbolic dynamics are applied to construct a description of two-person supergames, i.e., games involving infinite repetition of the same basis matrix game. The behavior of players choosing their moves based only on information about the m previous moves follows a stationary joint probability distribution. Equations for this distribution are derived and it is shown that a mixed extension of the basis game corresponds to its representation as a supergame with m = 0, i.e., with player behavior that ignores the effect of the game history on the choice of player strategies.

Open agent systems are multi-agent systems which any software agent may join. Entry may require compliance with particular stated conventions, such as use of an agent communication language and interaction protocol, or the making of a financial deposit. However, subject only to such conventions, any software agent may join. Because such agents may represent different human principals and typically will have been constructed by different software design teams, they may, in general, have conflicting goals, interests, beliefs and values. In these circumstances, which agent’s goals or beliefs prevail in the interaction will depend on the nature of the social and political relationships between the participants. In situations where the agents adhere to some hierarchical relationship inside the agent system, that agent or agents at the top of the hierarchy may have final decision-making authority. For example, in an auction interaction, the auctioneer may have the explicit power to determine the final allocation of the scarce resources being sought by the bidders. Power such as this may not reside in particular agents, but accrue to certain roles within the agent system, as in electronic institutions. However, if human interaction is any guide, in many open environments there will either be no such hierarchy, or what hierarchies there are may be contested by some participants. Indeed, this is already true of existing agent societies on the Internet. What structures are appropriate for agent societies in these circumstances? The absence of hierarchy means that the relationship between the participants is closer to one of equality; this in turn suggests that some form of democracy is appropriate when we consider the structure of these agent systems. Within the discipline of political philosophy, human democracy is a notion much debated, and there are several alternative normative theories of democracy. A designer