It's a very dry science of sorts with big political implications. This is a fascinating analysis of what has happened in this recession – essentially an unnecessarily steep rise in unemployment and then a matching steep decrease caused by all sorts of odd factors (mainly the huge rise in working hours by people in employment). But the bottom line is that it's unlikely we're going to get the rate that much lower any time soon: a drop of only 0.4 percent over the next two years looks likely.