Life on the road is full of surprises. Not all of them are bad.

In Abu Dhabi, I met the editors of an impressive English language newspaper start-up called The National. Later, someone who knew of my interest in cities showed me one of its articles, the best news account of life in an informal settlement I’ve ever read.

With gritty realism, the article shows that:

1. cities offer economic opportunities that don’t exist in rural areas, so people will endure urban living conditions that seem unimaginable to us;

2. city officials and real estate developers, guided by market incentives, typically want to push poor people out of urban areas, back to the countryside.

Moving back to rural areas versus living with indoor garbage piles and raw sewage running down from people upstairs? Surely these are not the only options.

It is possible to build apartments that poor people can afford to rent, ones that use very little land per person (the scarce resource near a city) because they are small and the buildings they are in have several floors.

If the number of people who can live in cities is artificially limited, the price per person for legal housing will increase to the point that no poor person can afford it. But if the supply of urban amenities can respond to demand, the market can clear and someone can make a profit selling urban amenities to “the bottom of the pyramid.”

The challenge is to remove the supply constraints. If cities are so valuable, why can’t the world supply more of them?

This post originally appeared on the NYU Stern Urbanization Project’s blog. To read the original post, click here.