Hi All, I'll try to keep this simple!
The market in bonds provides us with expected interest rates in the future. A schedule of interest rates known as the "Swap Curve" is one of the most used by economic forecasters.
As at 31/12/2010, the Swap Curve estimates the following approx rates (rounded):
2011: 1%
2012: 1.5%
2013: 3%
2014: 3.25%
2015: 3.75%
If you have a €100k mortgage, that would mean €7.5k extra in interest payments resulting from interest rate hikes. It would be comparable to moving immediately to a fixed rate 1.5% higher than the variable rate for 5 years.
If you take it as a given that banks will increase interest rates by at least 0.5% in the absence of interest rate increases, then this implies that anyone on a variable should be happy to fix at a rate that is not more than 2% higher than their current rate over a 5 year timeframe.
This will not apply to trackers as the fixing will cause you to lose your tracker forever, which is more difficult to quantify the cost of.
To put this idea in context, however, the same comparison done at 30/09/2010 would have suggested you should only be happy to fix if the rate is 1% above your current variable rate over a 5 year timeframe.
The change has been driven by the fact that inflation is expected to return sooner than expected as a result of Europe (Germany) recovering faster than expected.
These variables change daily and are the best info to hand in the fix or not decision. It shows just how uncertain it is as to what the correct course of action is.