Online Cake Cutting (published version)

TL;DR

This paper introduces an online version of the cake cutting problem, adapting classic fair division procedures to dynamic agent arrivals and departures, and evaluates their fairness and resistance to collusion.

Contribution

It extends traditional cake cutting methods to online settings, proposing fairness properties and analyzing their performance and collusion resistance.

Findings

Online cut-and-choose outperforms moving knife in collusion resistance.

Proposed procedures achieve online proportionality and envy-freeness.

Empirical results support the effectiveness of online cut-and-choose.

Abstract

We propose an online form of the cake cutting problem. This models situations where agents arrive and depart during the process of dividing a resource. We show that well known fair division procedures like cut-and-choose and the Dubins-Spanier moving knife procedure can be adapted to apply to such online problems. We propose some fairness properties that online cake cutting procedures can possess like online forms of proportionality and envy-freeness. We also consider the impact of collusion between agents. Finally, we study theoretically and empirically the competitive ratio of these online cake cutting procedures. Based on its resistance to collusion, and its good performance in practice, our results favour the online version of the cut-and-choose procedure over the online version of the moving knife procedure.