I don't see how you're ignoring all the countries that have had economies collapse. It's not impossible.
We're discussing a very specific type of economic collapse; one due to runaway growth and exhaustion of space/resources. If you have an example of that specific type of 'collapse' happening, I'd be most curious?
1. Scientific discovery and innovation. People were all in huge panic in the 17/18/19th century about the ability of our limited amount of land to feed the (exponentially-growing) populace, yet discovery of new methods/technologies increased the hypothetical yield such that the point became moot.
2. We live in a feedback-loop system. In the absence of perverse (and universal) government incentives, society will slow-down as resources become scarce. That is, until point number 1 kicks in again and the cycle starts fresh.