What exactly are these costs, and what's the most effective way to mitigate them or spread them more fairly? Sparse housing has costs, too. Very big costs, lik

What exactly are these costs, and what's the most effective way to mitigate them or spread them more fairly? Sparse housing has costs, too. Very big costs, like commute time and pollution. The fact that a developer might get rich in the process of creating dense housing is not really a problem for me.