The urge to measure everything by income leads to absurd results, like putting Saudi Arabia and the UAE near the top of the "housing affordability" list because they're flush with oil money, and for the same reason the United States.

> We really should have that lower end housing, I agree, but then we are comparing apples to Orenjis.

But that's the point. Someone in the US who makes 20% of the median household income still needs somewhere to live, and by refusing to provide smaller units, we make things cost more for everyone else too. Because now they have to spend their entire salary on housing and make up the rest with government assistance, which bids up housing costs for people in the middle -- who are also the ones footing the bill for subsidies made necessary by the high costs.

It's not just about the cost per square foot, it's also that small units aren't even available because the rules proscribe more units from being built on the same lot. The result is a de facto prohibition on smaller units because ordinarily it costs a similar amount to build a small number of large units and a large number of small units, but now the latter is unlawful and a small number of small units is uneconomical.

It's global in the sense that it's present in multiple countries, often for the same reasons. For example, the costs are high in the UK for similar reasons as in the US. But many of the comparisons just don't apply.

If you look at a country with a very low median income, of course housing costs a lot compared to the median income -- everything costs a lot compared to the median income. And housing in particular requires skilled labor and global commodities like timber and steel, which put a floor on the cost regardless of what local incomes are.

So housing in India or Vietnam costs a lot relative to local incomes because wood costs a lot relative to local incomes, even though housing there doesn't cost a lot in absolute terms. Which is not the problem in San Francisco, is it?