What measure of earnings should be compared to house prices?

If the share of homes bought using the joint income of a two-earner household has trended up over time, it is possible that a measure of the house price-to earnings ratio that uses average individual earnings data will make housing look more expensive than it is. But there has also been a rise in the share of one-person households and recalculating the ratio using a measure of household, rather than individual, earnings does not alter the fact that house prices currently look overvalued.