Crowdsourcing with Tullock contests: A new perspective

TL;DR

This paper introduces a novel Tullock contest-based incentive mechanism for crowdsourcing, replacing fixed prizes with contribution-dependent prizes, leading to significantly improved crowdsourcer utility and social welfare.

Contribution

It proposes a new Tullock contest design with contribution-based prizes, enhancing participation and utility in crowdsourcing beyond traditional fixed-prize contests.

Findings

Our mechanism outperforms the benchmark by over three times in utility.

It increases social welfare up to nine times compared to traditional contests.

The approach is suitable for rapid deployment in distributed web and mobile platforms.

Abstract

Incentive mechanisms for crowdsourcing have been extensively studied under the framework of all-pay auctions. Along a distinct line, this paper proposes to use Tullock contests as an alternative tool to design incentive mechanisms for crowdsourcing. We are inspired by the conduciveness of Tullock contests to attracting user entry (yet not necessarily a higher revenue) in other domains. In this paper, we explore a new dimension in optimal Tullock contest design, by superseding the contest prize---which is fixed in conventional Tullock contests---with a prize function that is dependent on the (unknown) winner's contribution, in order to maximize the crowdsourcer's utility. We show that this approach leads to attractive practical advantages: (a) it is well-suited for rapid prototyping in fully distributed web agents and smartphone apps; (b) it overcomes the disincentive to participate caused by players' antagonism to an increasing number of rivals. Furthermore, we optimize conventional, fixed-prize Tullock contests to construct the most superior benchmark to compare against our mechanism. Through extensive evaluations, we show that our mechanism significantly outperforms the optimal benchmark, by over three folds on the crowdsourcer's utility cum profit and up to nine folds on the players' social welfare.