Qu'est-ce que « Housing turnover, refinancing incentive » ?

Housing turnover is the part of prepayment that comes from home sales, defaults and curtailments, rising with loan age to a plateau and insensitive to rates. The refinancing incentive is the pool’s weighted-average coupon (WAC) minus the mortgage rate a borrower could get today: refinancing is worth it when the incentive exceeds the costs of doing so.