Congestion externalities are a well-known phenomenon in transportation and communication networks, healthcare etc. Optimization by self-interested agents in such settings typically results in equilibria which are sub-optimal for social welfare. Pigouvian taxes or tolls, which impose a user charge equal to the negative externality caused by the marginal user to other users, are a mechanism for combating this problem. In this paper, we study a non-atomic congestion game in which heterogeneous agents choose amongst a finite set of heterogeneous servers. The delay at a server is an increasing function of its load. Agents differ in their sensitivity to delay. We show that, while selfish optimisation by agents is sub-optimal for social welfare, imposing admission charges at the servers equal to the Pigouvian tax causes the user equilibrium to maximize social welfare. In addition, we characterize the structure of welfare optimal and of equilibrium allocations.
翻译:在交通和通信网络、医疗保健等场合,众所周知的外部影响现象是交通和通信网络、医疗保健等中众所周知的现象。 在这种环境下,自我利益分子优化通常导致平衡,而这种平衡对社会福利来说是次优的。 猪禽税或收费对用户征收与边际用户对其他用户造成的负面外部影响相等的用户收费,是解决这一问题的机制。 在本文中,我们研究了一种非原子拥挤游戏,其中各式各样的代理商选择了一定数量的多种服务器。服务器的延迟是其负荷的日益增强的功能。 代理人对拖延的敏感度各不相同。我们表明,尽管代理人的自私选择对社会福利是次优的,但在服务器上征收与Pigouvian税同等的入场费,导致用户平衡,以尽量扩大社会福利。此外,我们把福利和平衡分配的结构定性为最佳和平衡。