The Yo-yo theory

I was talking to someone the other day about the economy and how IT and security are affected by it and I made the following observation and analogy:

Everyone knows IT spending is important and can result in real benefit to the company however, there's a tendency to use yo-yo budgeting.

When things get tough, the yo-yo is dropped as spending slows and we expect IT to run on the bottom for as long as possible, but eventually we need to catch up and snap the yo-yo back up and we catch up on technology.

Maybe the reasoning is a bit simplistic (after all I'm an IdM architect, not an economist) but I think it holds up and I'm pretty sure that this model would extend beyond IT as well. I'm wondering how much the model holds, does a slower decline mean you can stay down longer or not? Does each department have it's own yo-yo?

Where's an economist when you need one?