Aggregate housing prices in the US have recently been approaching the levels seen at the peak of the housing bubble back in 2006. Indeed, in some locations they have gone higher than they did then, such as in San Francisco. This has led some to speculate that the US is getting back into a housing bubble again. Maybe, but probably not, and the reason is not something to be happy about: rising rents, especially for lowest income Americans who cannot afford to buy even a cheap house.
When in 2005 Robert Shiller published the second edition of his influential book, Irrational Exuberance, his new second chapter that documented the long historical path of price-rent ratios in US housing pretty much convinced anybody who looked at it that indeed the US was having a housing bubble as that ratio had been sharply rising and was at all time historical highs. Indeed, it would peak a year later, with prices falling while rents did not as we plunged into the crash that led to the Great Recession through many channels.
The Economist has provided some more detailed data on prices and rents for three major US cities, high growth San Francisco, more intermediate growth New York, and more slowly growing Philadelphia. Checking the various charts at this site one finds that San Francisco now has noticeably higher house prices than at the 2006 peak, New York has come up from its bottom by about a third to the former peak, and Philadelphia has nearly fully recovered its peak, but not quite. OTOH, price to rent ratios have behaved very differently. At the peak, San Francisco was at 30, but is now just at 20, although rising somewhat. New York's has not been rising at all, was at 25 at the peeak and now about 14 and stagnant. Philadelphia was at 15 at the peak, at 10 at its bottom, but now only at 11. It is simple arithmetic that if prices have been rising substantially while price to rent ratios have not been, then rents must be rising.
Dan Crawford, reposting work by New Deal Democrat at Angry Bear today, lays out more details on what is going on, including one graph that shows the steady rise in rents over time. More striking and disturbing is the information about rents being paid by lower income people, particularly the bottom third in income of renters. Their rents spiked noticeably in 2014 (data since not yet available), with the proportion of their incomes these people now paying on rent approaching 50%. This is a serious problem, and I do not know why exactly this is happening. But there has been little notice or publicity about it. In any case, it is precisely these people who are not able to afford to buy a house and thus must rent in order to live somewhere.
So, no, despite housing prices approaching former peaks, it does not look like we have a housing bubble (although possibly in a few locations). But it certainly looks like we have an acute low income rental housing crisis that has not been publicized that has become very severe, making life much harder for those at the bottom in what is supposedly a nicely recovering, almost "Goldilocks," economy.
Addendum: After posting this read today's Business section of the Washington Post where on p. 2 there is a fairly substantial article by Emily Badger detailing the cost of living problems for basics for the poor, nothing that transportation, food, and medical costs have also risen for the poor, although houising cost increases have been the most serious and reconfirming the figure that for the poorest third of renters, housing costs now consume nearly 50% of their income.