If the cities were net-negative economically, there'd be a net outflow of people from them (As anyone who can't make ends meet on the margins would pack up, lea

If the cities were net-negative economically, there'd be a net outflow of people from them (As anyone who can't make ends meet on the margins would pack up, leave, and create those vacancies.) Yet, that's not the case. There's an economic pull to cities, the are, on the net, more productive than the countryside (Because the proximity of people makes the cost of bringing goods and services to market very, very low.) The cost of land, in the long-term, rises to meet the economical productivity of an area. The reason that cities are so damn expensive is because they are productive.