Quid Pro Quo: A Mechanism for Fair Collaboration in Networked Systems

Abstract

Collaboration may be understood as the execution of coordinated tasks (in the most general sense) by groups of users, who cooperate for achieving a common goal. Collaboration is a fundamental assumption and requirement for the correct operation of many communication systems. The main challenge when creating collaborative systems in a decentralized manner is dealing with the fact that users may behave in selfish ways, trying to obtain the benefits of the tasks but without participating in their execution. In this context, Game Theory has been instrumental to model collaborative systems and the task allocation problem, and to design mechanisms for optimal allocation of tasks. In this paper, we revise the classical assumptions of these models and propose a new approach to this problem. First, we establish a system model based on heterogenous nodes (users, players), and propose a basic distributed mechanism so that, when a new task appears, it is assigned to the most suitable node. The classical technique for compensating a node that executes a task is the use of payments (which in most networks are hard or impossible to implement). Instead, we propose a distributed mechanism for the optimal allocation of tasks without payments. We prove this mechanism to be robust evenevent in the presence of independent selfish or rationally limited players. Additionally, our model is based on very weak assumptions, which makes the proposed mechanisms susceptible to be implemented in networked systems (e.g., the Internet).

Fair linking mechanisms for resource allocation with correlated player types

“…This solution has a very nice property that was already observed in our original work (QPQ with independent players [33]). The mechanism designer could aggregate players when studying a single player.…”

“…Previous work in the area of mechanism design for distributed systems [33] has already faced these problems dealing with tasks allocations in the presence of selfish or irrational independent player. However, when players are dependent (i.e., the distribution of their declared preferences are correlated) those solutions cannot guarantee the desired properties in terms of fairness and efficiency.…”

“…Related to this work, Engelmann and Grimm [8] presents experimental research on linking mechanisms. An algorithm called Quid Pro Quo (QPQ) [33] has been proposed as an application of this kind of mechanisms to distribute task executions fairly among independent players.…”

“…As mentioned, in [33] we have proposed a mechanism that we called Quid Pro Quo (QPQ) Mechanism. QPQ presents several interesting properties in relation to the efficiency in presence of selfish or rationally-limited players.…”

“…As mentioned previously, in this problem the outcome set is D = N , where an outcome of d ∈ D for resource r k means that r k is allocated to player d. In [33], we have proposed a QPQ algorithm that implements this function when the type of players follow mutually independent distributions. As in that work, we assume here that the type of each player is normalized using a Probability Integral Transform (PIT, see Sect.…”