Good point. I suppose median_home_price/median_income is a decent metric? Some stats to further the debate:

- https://www.numbeo.com/property-investment/rankings_by_count...

- https://knoema.com/infographics/hyjmcxd/housing-affordabilit...

- https://www.nationmaster.com/nmx/ranking/house-price-to-inco...

- https://www.statista.com/statistics/237529/price-to-income-r...