Surely more people are an asset for the local government, not a liability? You'd have 3x the tax revenue, 3x the purchasing power, plus the logistic efficiency that allows for local business to spring up and mass transportation to be viable.
That's the point the GP is trying to make: those services rely on property taxes, not income tax. So more people in the same area means either lower revenue per capita for the local government, or much higher taxes for the existing residents. Usually, proposing the second option is political suicide.
It depends on who the "more people" are. Schools are the vast bulk of many town budgets. Young families are a net user of town services and enough of them would drive higher property tax rates. (In my case, the town also has negligible commercial activity and no transit--and is spread out enough that transit is basically a non-starter.)
Maybe, maybe not. People are not equal. You can nly tax someone so much. 3 people making $10k/yr (this is below poverty in the US) at 100% is the same as 1 person make $100k at 30% - but the first group couldn't live after taxes while the second could.
Of course when the people are more equal your math works out. However things are never equal.
