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We provide an overview of experimental literature on contests and point out the two main phenomena observed in most contest experiments: (i) overbidding relative to the standard Nash equilibrium prediction and (ii) heterogeneous behavior of ex ante symmetric contestants. Based on the sample of contest experiments that we review, the median overbidding rate is 72%. We provide different explanations for the overbidding phenomenon, including bounded rationality, utility of winning, other-regarding preferences, probability distortion, and the shape of the payoff function. We also provide explanations for heterogeneous behavior of contestants based on differences in preferences toward winning, inequality, risk and losses, and demographic differences. Furthermore, we suggest mechanisms that can reduce overbidding and induce more homogeneous behavior. Finally, we discuss directions for future research. [ABSTRACT FROM AUTHOR]

Abstract: This article experimentally studies a two-stage elimination contest and compares its performance with a one-stage contest. Contrary to the theory, the two-stage contest generates higher revenue than the equivalent one-stage contest. There is significant over-dissipation in both stages of the two-stage contest and experience diminishes over-dissipation in the first stage but not in the second stage. Our experiment provides evidence that winning is a component in a subject''s utility. A simple behavioral model that accounts for a non-monetary utility of winning can explain significant over-dissipation in both contests. It can also explain why the two-stage contest generates higher revenue than the equivalent one-stage contest. [Copyright &y& Elsevier]

The tug-of-war is a multi-battle contest often used to describe extended interactions in economics, operations management, political science, and other disciplines. While there has been some theoretical work, to the best of our knowledge, this paper provides the first experimental study of the tug-of-war. The results show notable deviations of behavior from theory derived under standard assumptions. In the first battle of the tug-of-war, subjects often bid less, while in the follow-up battles, they bid more than predicted. Also, contrary to the prediction, bids tend to increase in the duration of the tug-of-war. Finally, extending the margin necessary to win the tug-of-war causes a greater reduction in bidding than either a decrease in the prize or greater impatience despite all three having the same predicted effect. These findings have implications both for theorists and practitioners. • We provide the first experimental study of the tug-of-war. • The results show notable deviations of behavior from theory. • In the first battle, subjects bid less than predicted. • In the follow-up battles, subjects bid more than predicted. • Bids increase in the duration of the tug-of-war. [ABSTRACT FROM AUTHOR]

We review the main economic models of war and conflict. These models vary in details, but their implications are qualitatively consistent, highlighting key commonalities across a variety of conflict settings. Recent empirical literature, employing both laboratory and field data, in many cases confirms the basic implications of conflict theory. However, this literature also presents important challenges to the way economists traditionally model conflict. We finish our review by suggesting ways to address these challenges. [ABSTRACT FROM AUTHOR]

This study provides a unified framework to compare three canonical types of contests: winner-take-all contests won by the best performer, winner-take-all lotteries where probability of success is proportional to performance, and proportional-prize contests in which rewards are shared in proportion to performance. We derive equilibria and observe outcomes from each contest in a laboratory experiment. Equilibrium and observed efforts are highest in winner-take-all contests. Lotteries and proportional-prize contests have the same Nash equilibrium, but empirically, lotteries induce higher efforts and lower, more unequal payoffs. Behavioral deviations from theoretical benchmarks in different contests are caused by the same underlying attributes, such as risk-aversion and the utility of winning. Finally, we find that subjects exhibit consistent behavior across different types of contests, with subjects exerting higher effort in one contest also exerting higher effort in another contest. [ABSTRACT FROM AUTHOR]

Many economic interactions rely on trust and trust violations can have serious economic consequences. Simple minimum standard rules are attractive because they prevent egregious trust violations. However, they may undermine more trusting and reciprocal (trustworthy) behavior that otherwise would have occurred, leading to worse outcomes. In an experimental trust game, we test the efficacy of exogenously imposed minimum standard rules. Rules damage trust and reciprocity, reducing economic welfare. While sufficiently restrictive rules restore welfare, trust and reciprocity never return. Results indicate that participants are concerned about payoffs while also using the game to learn about trust and trustworthiness of others. (JEL C72, C90, D63, D64, L51) [ABSTRACT FROM AUTHOR]

We conduct a field experiment on conflict in swimming pools. When all lanes are occupied, an actor joins the least crowded lane and asks one of the swimmers to move to another lane. The lane represents a contested scarce resource. We vary the actor's valuation (high and low) for the good through the message they deliver. Also, we take advantage of the natural variation in the number of swimmers to proxy for their valuation. Consistent with theoretical predictions, a swimmer's propensity to engage in conflict increases in scarcity and decreases in the actor's valuation. We complement the results with survey evidence. [ABSTRACT FROM AUTHOR]

Commitment problems are inherent to non-binding conflict resolution mechanisms, since an unsatisfied party can ignore the resolution and initiate conflict. We provide experimental evidence suggesting that even in the absence of binding contractual agreements individuals often avoid conflict by committing to the outcome of a conflict resolution mechanism. Commitment problems are mitigated to a greater extent for groups that opt-in to the conflict resolution mechanism, but only when opting-in is costly. Although conflict rates are higher when opting-in is costly than when it is free or exogenously imposed, commitment problems are greatly reduced among those groups who choose to opt-in. [ABSTRACT FROM AUTHOR]

Highlights: [•] We analyze a group contest with a group-specific public good prize. [•] Only the highest effort within each group represents the group effort. [•] In equilibrium at most one player in each group expends strictly positive effort. [•] There exists an equilibrium where the highest value players free-ride on others. [•] We provide conditions under which the set of equilibria can be restricted. [ABSTRACT FROM AUTHOR]

We study three triggers of conflict and explore their resultant emotional reactions in a laboratory experiment. Economists suggest that the primary trigger of conflict is monetary incentives. Social psychologists suggest that conflicts are often triggered by fear. Finally, evolutionary biologists suggest that a third trigger is uncertainty about an opponent’s desire to cause harm. Consistent with the predictions from economics, social psychology, and evolutionary biology, we find that conflict originates from all three triggers. The three triggers differently impact the frequency of conflict, but not the intensity. Also, we find that the frequency and intensity of conflict decrease positive emotions and increase negative emotions and that conflict impacts negative emotions more than positive emotions. [ABSTRACT FROM AUTHOR]

This article implements an experimental test of a game-theoretic model of equilibrium profiling. Attackers choose a demographic “type” from which to recruit, and defenders choose which demographic types to search. Some types are more reliable than others in the sense of having a higher probability of carrying out a successful attack if they get past the security checkpoint. In a Nash equilibrium, defenders tend to profile by searching the more reliable attacker types more frequently, whereas the attackers tend to send less reliable types. Data from laboratory experiments with financially motivated human subjects are consistent with the qualitative patterns predicted by theory. However, we also find several interesting behavioral deviations from the theory. [ABSTRACT FROM AUTHOR]

The attack-and-defense game is a game in which an attacker (a group of attackers) has an incentive to revise the status quo and a defender (a group of defenders) wants to protect it. The asymmetry in objectives creates incompatible interests and results in a mixed-strategy Nash equilibrium. However, this equilibrium could be heavily impacted by behavioral considerations.

Acute obstructive pyelonephritis (AOP) is a urological life-threatening inflammatory condition that initially requires immediate urinary drainage and simultaneous prescribing of highly effective targeted antibacterial treatment. The empirical antibacterial therapy is always prescribed before urine culture and susceptibility testing are done. Percutaneous nephrostomy (PNS) and ureteral stenting (US) are the two options for urinary drainage in obstructed kidneys, while fluoroquinolones and 3(rd) generation cephalosporins are the main groups of antibacterial drugs that are recommended and are available for empirical AOP therapy. In our study we aimed to compare efficacy of fluoroquinolone ciprofloxacin vs 3(rd) generation cephalosporin ceftazidime in empirical antibacterial treatment of patients with acute obstructive pyelonephritis. We also tried to analyze the impact of urinary drainage option on cure rates. 241 AOP patients were randomized into two groups: Group 1, n=124 pts in whom percutaneous nephrostomy was performed urinary drainage and Group 2, n=117 pts, in whom ureteral stenting was made. Then each abovementioned group was also randomized into equal two subgroups (ciprofloxacin vs ceftazidime) depending on the empiric antibacterial treatment which was chosen. Our results revealed that cure rates in patients treated by ceftazidime were higher than those who were treated by ciprofloxacin. At late follow-up, the clinical cure rate in PNS group treated by ceftazidime was 95.2% vs 83.6% in ciprofloxacin arm, while the microbiological cure rates were 92.9% vs 80.0% correspondingly (p<0.05). At late follow-up, the clinical cure rate in US group treated by ceftazidime was 86.4% vs 74.1% in ciprofloxacin arm while the microbiological cure rates were 82.4% vs 69.4% correspondingly (p<0.05). We also concluded that percutaneous nephrostomy ensures a better clinical cure than ureteral stenting at early and late follow-ups regardless of the drug regimes which were chosen. Thus, in our opinion, percutaneous nephrostomy combined with ceftazidime treatment can be considered as the most effective option in patients with acute obstructive pyelonephritis.

Till now numerous reports have depicted the different constricting devices (CDs) previously threaded on the penis for obtaining of sexual pleasure or/and prolonged erection. The causes of CD bearing on the penis are sexual or autoerotic actions. Here we present two cases of successful removal of a metal device from a penis that was associated with trauma grade II according to Bhat et al. The techniques used are also described. In both cases the essential features of successful device removal were its motionless fixation by nippers or vice combined with placing a metal plate under the constricting ring. The CDs were successfully removed without complications.