At least one economist has suggested that even large developing-country cities are economically too small. What argument would support this contention? How would you argue against it?

What will be an ideal response?

Cities could be considered too small if the demand and supply of urban services are determined in a perfect market: migration indicates cities can accept new populations. Imperfect information, however, suggests that migrants continue to come even though services are insufficient to support them. (Information here is a public good to the extent that overpopulated cities suffer considerable negative externalities.)