The challenge is that public sanitation isn’t something the market necessarily provides. Toilets cost money, but defecating in the street is free. If I install a toilet, I bear all the costs, while the benefits of the cleaner street are felt by everyone. In economic parlance, that’s what is known as a positive externality—and goods that have positive externalities tend to be bought at a slower pace than society, as a whole, would prefer.
Positive externality
