<prompt> Human: My credit union offers mortgages with NO PMI. However, they only offer 15 and 20 year fixed mortgages. the 20 year fixed puts the payments a little out of reach. a 51 ARM puts the payments right in the sweet spot. My questions is, why cant I take the 51 ARM and then refinance later to the 20 year fixed? I know Ill be making more money then and will have some of it paid off.x200B;thoughts?  <response>: Google U.S. housing crisis. Your dubious logic is the consumer-side rationalization that helped cause the problem. 