The argument is density. Things tend to be cheaper per capita, when density is high.
I don't buy it thought. I think the reason why the spend is less in Europe is due to higher salary equality - good people take job in government because the salary is only 50% higher in private sector (for tech, even less for other areas).
There are only a couple of US states less dense than e.g. Norway, and even in those states the vast majority of the population live in small, higher density areas.
The areas where the vast majority of Americans actually live are fairly high density.
Some cost might come down to density, but not much.
I don't buy it thought. I think the reason why the spend is less in Europe is due to higher salary equality - good people take job in government because the salary is only 50% higher in private sector (for tech, even less for other areas).