[AnthonyMouse]

> This is a conjecture that as far as I know does not match what actually happens, which is that the new infrastructure is paid by debt, and the 4 new taxpayers will not have paid off the debt before the infrastructure needs replacement, paid for by more debt.

If four taxpayers aren't paying the amount of taxes required to fund the infrastructure needed by four taxpayers then your city is already bankrupt and zoning and planning is irrelevant.

> If it was 600 new units rather than 4

If it was literally only 4 units then you shouldn't need any new infrastructure anyway. Nothing should be operating with margins that thin to begin with.

If it's 4 units here, 4 units there then it adds up to hundreds which is the thing you admit isn't a problem.