[robertlagrant]

Ah - yes. I see the difference now. I don't really understand why the US does it that way, then. Why not do shorter-term mortgages that price in risk? Or is it doing that in a way I don't understand? (But then why is the government involved?)

[bradleyjg]

Well that’s exactly it. For the homeowner 30 year fixed is great. You know that your mortgage payment is never going to go up, regardless of what happens with the interest rate. On the flip side, if interest rates fall since we have no prepayment penalties you can just refinance and pay less.

It’s great for the borrower, which means it’s bad for the lender. There’s some spread of interest over treasuries that might make it worth it for them anyway—like if it was the 30 year bond rate plus 10% or something, but the spreads are narrow.

That’s why I said I don’t think it would exist accept for extensive government intervention, because it’s such a good deal.

As for why the government decided to get so involved, it goes way back to before my time. Now they’d have a hard time extracting themselves without making a lot of homeowners very mad.