The supply of local public goods would obey principles that are not fundamentally different from those governing the efficient supply of differentiated goods. All these results rest on the assumption of an efficient land market. This suggests that the problem of land property rights should receive more attention than it does nowadays. However, the conditions for a competitive market for cities to work might be hard to achieve. First, the instrument menu available to developers is likely to be constrained. Second, nonreplicability and indivisibility may give rise to additional difficulties. In either case, the market would fail to sustain the optimum for reasons which are not always well understood.