As a story in today’s Wall Street Journal makes clear, the housing affordability crisis has gone global. It’s not just San Francisco where housing, both owned and rental, has soared out of reach; it’s also Seoul and Dublin and Berlin. "In Canada, New Zealand and Norway," the Journal reports, "the home price-to-income ratio … is at its highest level ever."

The Journal article doesn’t provide a deep dive into the causes behind this go-sleep-in-a-manger pandemic, but it certainly looks like yet another manifestation of Piketty’s r>g—that is, the rate of return on investment, in this case in housing, is greater than the growth, in this case, not of nations’ incomes, but rather the income of those nations’ median residents. Though the Journal doesn’t reference it, the purchase of many thousands of for-sale and rental properties by major corporations and investors is now a global phenomenon. These corporations and investors have enough market share to send housing costs skyward, and enough cash cushion to hang on to a property until the bids for it clear a high bar. Such has been the case in Berlin, a city disproportionately of renters, where private equity and hedge funds have purchased roughly 200,000 housing units since 1990.

In Sunday’s German elections, Berliners pushed back at these latter-day Nosferatus who’ve threatened their previously affordable burg. In an advisory referendum, they voted by a 56 percent to 39 percent margin to instruct the city government to purchase the housing owned by private real estate companies and investors that own more than 3,000 units. If the government takes this recommendation, it would transfer roughly 15 percent of Berlin’s housing (about 240,000 units) from private to public ownership. Of course, purchasing on that scale doesn’t come cheap; a purchase earlier this month of 15,000 apartments from two corporations will cost the city $2.9 billion.

It’s by no means clear that Berlin’s city government will take the advice that this advisory referendum offered, though it may well continue its more incremental buyouts, such as the one it made earlier this month—in response, surely, to its sense that the referendum would pass. It is clear, alas, that no American city government would venture such a move, but tenant and home-buyer advocates here in the U.S. should nonetheless feel emboldened by their Berlin comrades to push for rent control (with no vacancy decontrol) and new public housing, as the cost of housing continues to soar while incomes lag far behind.