This is just yet another example of good government intentions gone wrong. Low rates, in addition to driving prices up by giving more buying power across the board, has skewed what investors deem to be acceptable ROI. When bonds are paying 2%, a 5% cap rate, in addition to any equity building, seems pretty nice. One thing I did not see mentioned is that income limits on affordable housing, by themselves, will not necessarily deter investors, who may be able to shell-game their incomes into whatever they need to be to get under the bar.