PRIVATE VERSUS PUBLIC MONEY*
用无承诺无执行的匹配模型，比较生产性（红色）与非生产性（绿色）代理人发行货币的效率，发现非生产代理人发行的绿色票据成本更低、能实现更多配置，因此应由非生产代理人（对应公共物品生产者）发行货币。
I show that the nature of agents' production determines whether they should issue money. I use a matching model with no commitment and no enforcement. Some agents can produce goods, whereas others are unproductive. All agents can produce at a cost a distinguishable, intrinsically useless but durable good: notes. Productive agents produce red notes whereas unproductive agents produce green notes. I find that green notes are the most efficient means of exchange, as they implement more allocations than red notes and at a lower cost. Therefore, unproductive agents should issue money. I associate unproductive agents to agents producing public goods.