Public policy does more than enough already to reward sprawl and punish urban centers. Billions for freeways and a pittance for transit, FHA bias towards single family homes, etc. For the environment and the economy, we should be rewarding and encouraging people who move to megacities.

To make that worse, historically problematic movements like the Nazis, the Khmer Rouge and large parts of the Chinese communism found better support in rural areas. I strongly recommend Ian Buruma's "Occidentalism". It's short, packed with information, well researched and completely changed how I see the world. I would go so far to say that we need everything we can to have as few people live in rural areas as possible. Otherwise we will keep getting movements of rural people feeling left behind by the cold, calculating, greedy and immoral urban dwellers which will ultimately result in them yet again dragging everything down with them.