European Business Schools Librarian's Group
Home About Series Subject/JEL codes Advanced Search
HEC Paris. Research Department Les Cahiers de Recherche - HEC Paris

No 662:
Free Access to the Commons: Random Priority versus Average Cost

Herve CRES and Herve MOULIN

Abstract: A technology with increasing marginal costs produces indivisible units of service. Each agent wants at most one unit of service. We compare two natural mechanisms where users have free access to the technology. In one mechanism, Average Cost, each user pays the same average cost, in the other, Random Priority, users are randomly ordered (without bias) and successively offered to buy at the true marginal cost.

Both mechanisms, AC and RP, lead to inefficient overproductions. Which one leads to a less severe tragedy ? We show that RP tends to overproduce less but that which game collects more social surplus depends much on the configuration of the demand (namely the social value of the goods produced).

We give general results as well as canonical examples, describing demand and cost profiles for which one mechanism outperforms the other. We find that the key element for the comparison is the crowding ratio, i.e., the number of potential users over the number of units of output users can afford: (1) we prove that the more crowded the commons, the more RP outperforms AC, and (2) we exhibit a threshold value of 2.4 for the crowding ratio beyond which RP strongly outperforms AC, and beneath which AC only mildly outperforms RP. Thus the Random Priority mechanism offers a (partial) probabilistic resolution of the tragedy of crowded commons.

Keywords: tragedy of the commons; increasing marginal cost; scheduling; cooperative production; priority; (follow links to similar papers)

JEL-Codes: D60; D62; D72; (follow links to similar papers)

65 pages, November 2, 1998

Download Statistics

Questions (including download problems) about the papers in this series should be directed to Sandra Dupouy ()
Report other problems with accessing this service to Sune Karlsson () or Helena Lundin ().

Programing by
Design Joakim Ekebom

Handle: RePEc:ebg:heccah:0662 This page was generated on 2014-12-14 17:56:14