The housing market is in the midst of a bubble or a gradual recovery, depending on who you ask. Analysts on either side of the debate point to the agency dominance of the mortgage market as one of the factors driving up home prices. Peter Wallison, a senior fellow at the American Enterprise Institute, warned last week that the housing market is in the middle of another bubble. Housing bubbles become visible and can legitimately be called bubbles when housing prices diverge significantly from rents, he wrote in an op-ed published in the New York Times. Wallison pointed...