Proportional Fee vs. Unit Fee: Competition, Welfare, and Incentives*
比较了竞争性网络中单位费用与比例费用对社会福利的影响，发现需求为次凸或等弹性时比例费用更优，而需求超凸且竞争较弱时单位费用更优，比例费用是各网络的占优策略但常导致囚徒困境。
This paper compares social welfare for a unit versus a proportional fee on competing networks. When demand is sub‐convex or isoelastic, proportional fee welfare dominates unit fee and the comparison is independent of network competition. When demand is super‐convex, however, unit fee welfare dominates proportional fee if network competition is sufficiently weak. Dominance of unit fee is more likely when network competition weakens or if merchants must single‐home. For competing networks, proportional fee is each network’s dominant strategy but often leads to a Prisoners’ Dilemma that hurts not only networks but also merchants.