Yes, I wouldn't argue that personal finances are an exercise in 'pure' economics; sentiment and risk appetite are significant. But I still think too many people overpay their mortgage as a default without really thinking their options through. I know I used to! Then someone pointed out to me that, instead of overpaying, say, £200 a month, if I put it into a pension, my employer would match it, plus HMRC would give me 40% again in tax relief. For the same cost to me, it's £560 invested (typically at a higher rate), rather than £200. Over a long time and compounded that's a massive difference.