There is a confluence of at least two government failures behind the emergence of modern suburbs:

* government officials, pushed by NIMBY SFH owners and anti-profit left wing groups, restricting zoning/housing-development in major economic nexuses where the most job opportunities exist, leading to pressure to develop the adjacent suburbs as they are the next best location for housing.

* taxpayer funded left-wing groups pushing for social housing and social services in city cores, leading to neighbourhoods with high concentrations of low-income residents that become breeding grounds for crime, and cause urban decay that leads to the flight of middle class taxpayers to safer suburbs.