<Unless they're colluding, they'll keep building if it's profitable to do so.> if it's profitable over the long term. Keep in mind that builders have to alloc

<Unless they're colluding, they'll keep building if it's profitable to do so.> if it's profitable over the long term. Keep in mind that builders have to allocate ever-increasing percentages of units to "below-market housing". Then, with the current bubble bursts, they're stuck with the below-market renters but will be scrambling to fill the rest of the units.