This article is a good explanation: http://time.com/3031079/suburbs-will-die-sprawl/ http://time.com/3031079/suburbs-will-die-sprawl/ There are economies of sc

This article is a good explanation: http://time.com/3031079/suburbs-will-die-sprawl/ http://time.com/3031079/suburbs-will-die-sprawl/ There are economies of scale involved in building infrastructure for many people. If you have a low population density in an area (like a suburb) you can't collect enough tax to pay for the infrastructure (which is more spread out, while there are fewer people to pay for it). That money has to come from somewhere. In the article it's Federal grants. Where do you think the money for those Federal grants comes from? Suburbs are fundamentally unsustainable. There are not enough people there to pay for the infrastructure. That infrastructure is more expensive because it has to cover a larger area to serve a given number of people.