Contest Design: An Experimental Investigation

This paper experimentally compares the performance of four simultaneous lottery contests: a grand contest, two multiple prize settings (equal and unequal prizes), and a contest which consists of two subcontests. Consistent with the theory, the grand contest generates the highest effort levels among all simultaneous contests. In multi-prize settings, equal prizes produce lower efforts than unequal prizes. The results also support the argument that joint contests generate higher efforts than an equivalent number of subcontests. Contrary to the theory, there is significant over-dissipation. This over-dissipation can be partially explained by strong endowment size effects. Subjects who receive higher endowments tend to over-dissipate, while such over-dissipation disappears when the endowments are lower. This behavior is consistent with the predictions of a quantal response equilibrium. We also find that less risk-averse subjects over-dissipate more.rent-seeking, contest, contest design, experiments, risk aversion, over-dissipation

Experimental Comparison of Multi-Stage and One-Stage Contests

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.rent-seeking, contest, contest design, experiments, risk aversion, over-dissipation

Strategically Equivalent Contests

Using a two-player Tullock-type contest, we show that intuitively and structurally different contests can be strategically equivalent. Strategically equivalent contests generate the same best response functions and, as a result, the same equilibrium efforts. However, strategically equivalent contests may yield different equilibrium payoffs. We propose a simple two-step procedure to identify strategically equivalent contests. Using this procedure, we identify contests that are strategically equivalent to the original Tullock contest, and provide new examples of strategically equivalent contests. Finally, we discuss possible contest design applications and avenues for future theoretical and empirical research

The Equivalence of Contests

We use a Tullock-type contest model to show that intuitively and structurally different contests can be strategically and revenue equivalent to each other. We consider a two-player contest, where outcome-contingent payoffs are linear functions of prizes, own effort, and the effort of the rival. We identify strategically equivalent contests that generate the same family of best response functions and, as a result, the same revenue. However, two strategically equivalent contests may yield different equilibrium payoffs. Finally, we discuss possible contest design applications and avenues for future theoretical and empirical research.rent-seeking, contest, spillover, equivalence, revenue equivalence, contest design

Optimal Crowdsourcing Contests

We study the design and approximation of optimal crowdsourcing contests. Crowdsourcing contests can be modeled as all-pay auctions because entrants must exert effort up-front to enter. Unlike all-pay auctions where a usual design objective would be to maximize revenue, in crowdsourcing contests, the principal only benefits from the submission with the highest quality. We give a theory for optimal crowdsourcing contests that mirrors the theory of optimal auction design: the optimal crowdsourcing contest is a virtual valuation optimizer (the virtual valuation function depends on the distribution of contestant skills and the number of contestants). We also compare crowdsourcing contests with more conventional means of procurement. In this comparison, crowdsourcing contests are relatively disadvantaged because the effort of losing contestants is wasted. Nonetheless, we show that crowdsourcing contests are 2-approximations to conventional methods for a large family of "regular" distributions, and 4-approximations, otherwise.Comment: The paper has 17 pages and 1 figure. It is to appear in the proceedings of ACM-SIAM Symposium on Discrete Algorithms 201

Parallel Contests

A problem of Parallel Contests is raised and modeled. The equilibria in final situations of parallel contests are analyzed and characterized and the behaviours of contestants with different abilities’ parameters are explained. Given that the values of the prizes in the two contests are different, in equilibrium a group of strong players prefer entering into the contest with a higher prize. However, except the group of stronger ones, in equilibrium others will enter into both contests because they obtain equal expected revenue from the two contests, though these weak ones do not have equal probabilities to enter into the two parallel contests. Under the condition of rationalizability, this paper characterizes the respective distributions of contestants’ abilities in the two parallel contests, proves the existence of the equilibrium in parallel contests and completes the analysis of the parallel contests from the perspective of contestants.Parallel contests, Contest, Strategic behaviours

When Less is More: Rationing and Rent Dissipation in Stochastic Contests

This paper shows how to maximize revenue when a contest is noisy. We consider a case where two or more contestants bid for a prize in a stochastic contest with proportional probabilities, where all bidders value the prize equally. We show that by fixing the number of tickets, thus setting a limit to total expenditures, it is possible to maximize the auctioneer’s revenue and obtain (almost) full rent dissipation. We test this hypothesis with a laboratory experiment. The results indicate that, as predicted, revenue is significantly higher in a lottery with rationing than in a standard lottery. On the other hand, an alternative rationing mechanism that does not limit total expenditures fails to increase revenue relative to a standard lottery.

Markets for Influence

We specify an oligopoly game, where firms choose quantity in order to maximise profits, that is strategically equivalent to a standard Tullock rent- seeking game. We then show that the Tullock game may be interpreted as an oligopsonistic market for in?uence. Alternative specifications of the strategic variable give rise to a range of Nash equilibria with varying levels of rent dissipation

Innovation Contests with Entry Auction

We consider procurement of an innovation from heterogeneous sellers. Innovations are random but depend on unobservable effort and private information. We compare two procurement mechanisms where potential sellers first bid in an auction for admission to an innovation contest. After the contest, an innovation is procured employing either a fixed prize or a first-price auction. We characterize Bayesian Nash equilibria such that both mechanisms are payoff-equivalent and induce the same efforts and innovations. In these equilibria, signaling in the entry auction does not occur since contestants play a simple strategy that does not depend on rivals' private information