ABSTRACT
It is a rare moment in the world of demographic research when four things coincide: a profound global trend presents itself; the conceptual tools needed to analyze it and rich empirical resources are available; the trend has drawn the attention of closely allied fields and occasioned an outpouring of work by scholars in these fields; and yet the path forward lacks the signposts that would normally have been established by previous research. This is the situation facing demographers as they contemplate the cities of poor countries. The prospects are inviting, but for demographers, at least, this is an urban frontier.
