Surplus procedure

Surplus procedure

The surplus procedure (SP) is a fair-division protocol for cutting cake in a way that achieves proportional equitability between 2 people.

The surplus procedure was devised by Steven J. Brams, Michael A. Jones, and Christian Klamler in 2006.

In a nutshell, the procedure serves as an expansion of the "you cut I choose" method, having both participants serve as cutters. It has both participants privately disclose where they consider a fair halfway cut-point to be for the cake to a neutral arbitrator, who resolves the division of cake as follows:

If the cut location is the same for both, the cake is divided along the agree-upon line. # If the cut location differs (perhaps due to one area of the cake being valued more highly by one of the two for it containing the candle or more berries), then each participant is given "half" the cake according to their differing definitions, leaving a central column of surplus cake to be shared. The arbitrator "gives each person the same proportion of the cake that remains, called the surplus, as he or she values it".

Criticisms of the paper There have been a few criticisms of aspects of the paper. In effect the paper should cite a weaker form of Pareto optimality and suppose the measures are always strictly positive.

See also * [[adjusted-winner-procedure]] * Approval voting

References