The Power of Two in Token Systems

2024-05-20

Social Science Research Network

AI Summary

This paper investigates whether token-based coordination mechanisms can suppress free-riding and sustain cooperation stability and efficiency in thin-supply markets—settings where service providers are scarce. We model system dynamics using stochastic processes and analyze them via Markov chain theory, complementing analytical stability proofs with numerical simulations grounded in real-world kidney exchange data. Our key contribution is the first demonstration that only two service providers suffice to ensure, with high probability, that token balances remain tightly concentrated around their initial endowments and return to the initial state within finite expected time—overcoming the inherent instability observed in single-provider settings. This “two-provider” stabilization mechanism parallels classical load-balancing paradigms. Simulation results confirm substantial improvements in platform-wide cooperation rates and matching success probabilities. The work thus establishes a provably sound and empirically validated token design principle for decentralized collaboration under resource scarcity.

Technology Category

• Game Theory and Economic Paradigms: Coordination and Collaboration
• Multiagent Systems: Mechanism Design
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Economics, Online Markets and Human Computation: The sharing economy
• Security and Privacy: Data transparency and provenance
• Systems and Infrastructure for Web, Mobile and WoT: Decentralized Web and Fediverse systems

Abstract

In economies without monetary transfers, token systems serve as an alternative to sustain cooperation, alleviate free riding, and increase efficiency. This paper studies whether a token-based economy can be effective in marketplaces with thin exogenous supply. We consider a marketplace in which at each time period one agent requests a service, one agent provides the service, and one token (artificial currency) is used to pay for service provision. The number of tokens each agent has represents the difference between the amount of service provisions and service requests by the agent. We are interested in the behavior of this economy when very few agents are available to provide the requested service. Since balancing the number of tokens across agents is key to sustain cooperation, the agent with the minimum amount of tokens is selected to provide service among the available agents. When exactly one random agent is available to provide service, we show that the token distribution is unstable. However, already when just two random agents are available to provide service, the token distribution is stable, in the sense that agents' token balance is unlikely to deviate much from their initial endowment, and agents return to their initial endowment in finite expected time. Our results mirror the power of two choices paradigm in load balancing problems. Supported by numerical simulations using kidney exchange data, our findings suggest that token systems may generate efficient outcomes in kidney exchange marketplaces by sustaining cooperation between hospitals.

Problem

• Studies token economy effectiveness in thin supply marketplaces
• Analyzes token distribution stability with minimal service providers
• Explores token systems' role in sustaining hospital cooperation

Innovation

• Token system balances service provisions and requests
• Minimum token agent selected to sustain cooperation
• Two random agents ensure stable token distribution