Inequality is usually measured by comparing incomes across households within a country. But there is also a different kind of inequality: in the affordability of homes across cities. The impact of this form of inequality is no less worrying.
In many of the world’s urban centers, homes are becoming prohibitively expensive for people with moderate incomes. As a city’s real-estate prices rise, some inhabitants may feel compelled to leave. Of course, if that inhabitant already owned a house there that they can sell, they may regard the price increase as a windfall that they can claim by departing. If not, however, they may be forced out with no compensation.
The consequences are not just economic. People may be forced out of cities where they have spent their entire lives. Leaving amounts to losing lifelong connections, and therefore can be traumatic. If too many lifelong inhabitants are driven out by rising housing prices, the city itself suffers from a loss of identity and even culture.
As such people depart, an expensive city gradually becomes an enclave of high-income households, and begins to take on their values. With people of various income levels increasingly divided by geography, income inequality can worsen and the risk of social polarization – and even serious conflict – can grow.
As this year’s Demographia International Housing Affordability Survey shows, there are already massive disparities across major global cities (measured by the ratio of median home prices to median household income). A high ratio correlates with high pressure for people to leave.
This year’s survey, which covered 92 cities in nine countries, showed that, as of late 2016, Hong Kong had the least affordable housing, with a price-to-income ratio of 18.1. That means that paying off a 30-year mortgage on a median-price home would cost a median-income buyer more than half of their income – and that is without interest. Mortgage rates are low in Hong Kong, but not zero, suggesting it is just about impossible for a median-income household to purchase a home there without access to additional funds from, say, a parent, or, if the buyer is an immigrant, from abroad.