The navy of Athens during the democratic period (ca. 480-322 BCE) was largely financed and managed by wealthy citizens who undertook a public service, or liturgy, to maintain a warship for a year. With reference to a model of decisions made by the citizens eligible to undertake the liturgy, the author argues that the successive reforms to the institution were designed in ways and introduced at times to preserve its potential both to raise revenue and to remain popular. The first and second reforms performed these tasks by increasing the incentives for the citizens most willing to spend their money to undertake the liturgy; the third did so by reducing free riding.