 This is a study that looks at how people's decision to refinance their mortgages depends in the most trivial way on the benefits to doing it. As it turns out, that has a very important interaction with how powerful monetary policy is. So in periods when there are large gains to refinancing, if the Federal Reserve Board, the particular focus of our interest, lowers interest rates, that can have a very powerful effect on people's desired consumption, partly because they have a lower interest rate that they're paying, but also because when they refinance, they can take equity out of their home and use that to get any around borrowing constraints they have. The reason that's very relevant is we're able to quantify empirically and in our model the costs of keeping interest rates low for such a long period of time. So as you know, both in Europe and the United States, interest rates have been very low. What that means is in this situation, if the ECB, certainly in the United States, cuts interest rates, it's not going to have a lot of power. So if we get a big shock, we're not going to get a lot of juice, so to speak. Moreover, even if we normalize interest rates, it will take a long time to regain the power of monetary policy. So the bottom line is we're in a difficult situation. Interest rates have been low for a long time. We don't have a lot of room to cut interest rates a lot more, and our model and results say that a normal cut will not be as powerful as it normally would.