Unifying Contests: from Noisy Ranking to Ratio-Form Contest Success Functions

This paper proposes a multi-winner noisy-ranking contest model. Contestants are ranked in a descending order by their perceived outputs, and rewarded by their ranks. A contestant's perceivable output increases with his/her autonomous effort, but is subject to random perturbation. We establish, under plausible conditions, the equivalence between our model and the family of (winner-take-all and multi-winner) lottery contests built upon ratio-form contest success functions. Our model thus provides a micro foundation for this family of often studied contests. In addition, our approach reveals a common thread that connects a broad class of seeming disparate competitive activities and unifies them in the nutshell of ratio-form success functions.Multi-Winner Contest; Contest Success Function; Noisy Ranking

Contest design and optimal endogenous entry

This paper derives the effort-maximizing contest rule and the optimal endogenous entry in a context where potential participants bear fixed entry costs. The organizer is allowed to design the contest under a fixed budget with two strategic instruments: he sets the value of the prize purse, and arranges a monetary transfer (entry subsidy or fee) for each participating contestant. In other words, the budget can either be used to subsidize participation or an entry fee can be charged to fund the prize purse. The results show that the optimally designed contest attracts exactly two participating contestants in its unique subgame perfect equilibrium (when there is a positive fixed entry cost) and extracts all the surplus from participating contestants. The study also shows that the direction and amount of the monetary transfer depend on the magnitude of the entry cost: the contest organizer subsidizes entry when contestants bear substantial entry costs, but charges an entry fee to fund the prize purse whenever the entry cost is sufficiently low.Contest; Endogenous Entry; Entry Cost; Subsidy; Entry Fee

Unifying Contests: from Noisy Ranking to Ratio-Form Contest Success Functions

This paper proposes a multi-winner noisy-ranking contest model. Contestants are ranked in a descending order by their perceived outputs, and rewarded by their ranks. A contestant's perceivable output increases with his/her autonomous effort, but is subject to random perturbation. We establish, under plausible conditions, the equivalence between our model and the family of (winner-take-all and multi-winner) lottery contests built upon ratio-form contest success functions. Our model thus provides a micro foundation for this family of often studied contests. In addition, our approach reveals a common thread that connects a broad class of seeming disparate competitive activities and unifies them in the nutshell of ratio-form success functions.Multi-Winner Contest; Contest Success Function; Noisy Ranking

The beauty of "bigness" in contest design: merging or splitting?

This paper studies in a multiple-winner contest setting how the total efforts may vary between a grand contest and a set of subcontests. We first show that the rent-dissipation rate increases when the numbers of contestants and prizes are "scaled up". In other words, the total efforts of a contest exhibit a striking "increasing return to scale" property: when the numbers of contestants and prizes scale up proportionally, the total efforts of the contest increase more than proportionally. Thus, the total efforts must increase when a set of identical subcontests are merged into a grand contest. Equivalently, the total efforts decrease when a grand contest is evenly divided. We further allow the grand contest to be split into uneven subcontests. We show that under a mild and plausible condition (regular contest technology), the grand contest generates more efforts as compared to any split contests.Contests; Multiple-winners; Efforts; Size; Replication

Repeatable classical one-time-pad crypto-system with quantum mechanics

Classical one-time-pad key can only be used once. We show in this Letter that with quantum mechanical information media classical one-time-pad key can be repeatedly used. We propose a specific realization using single photons. The reason why quantum mechanics can make the classical one-time-pad key repeatable is that quantum states can not be cloned and eavesdropping can be detected by the legitimate users. This represents a significant difference between classical cryptography and quantum cryptography and provides a new tool in designing quantum communication protocols and flexibility in practical applications. Note added: This work was submitted to PRL as LU9745 on 29 July 2004, and the decision was returned on 11 November 2004, which advised us to resubmit to some specialized journal, probably, PRA, after revision. We publish it here in memory of Prof. Fu-Guo Deng (1975.11.12-2019.1.18), from Beijing Normal University, who died on Jan 18, 2019 after two years heroic fight with pancreatic cancer. In this work, we designed a protocol to repeatedly use a classical one-time-pad key to transmit ciphertext using single photon states. The essential idea was proposed in November 1982, by Charles H. Bennett, Gilles Brassard, Seth Breidbart, which was rejected by Fifteenth Annual ACM Symposium on Theory of Computing, and remained unpublished until 2014, when they published the article, Quantum Cryptography II: How to re-use a one-time pad safely even if P=NP, Natural Computing (2014) 13:453-458, DOI 10.1007/s11047-014-9453-6. We worked out this idea independently. This work has not been published, and was in cooperated into quant-ph 706.3791 (Kai Wen, Fu Guo Deng, Gui Lu Long, Secure Reusable Base-String in Quantum Key Distribution), and quant-ph 0711.1642 (Kai Wen, Fu-Guo Deng, Gui Lu Long, Reusable Vernam Cipher with Quantum Media).Comment: It was submitted to PRL in 2004. We designed a protocol to use repeatedly a one-time-pad to transmit ciphertext using single photons. The idea was proposed by Bennett, Brassard, Breidbart in 1982. Unknowing their work, we rediscovered this idea independently. We publish it here in memory of Prof. Fu-Guo Deng (1975.11.12-2019.1.18), who died after two years heroic fight with pancreatic cance