Keen then goes on to present a model that does include price dynamics. That model is not due to Keen, but to Schandl, and is of 2011 vintage, indicating that it was made after the crisis and cannot therefore cannot be regarded as a prediction. Note that in that Schandl (2011) model, as presented by Keen, the economic collapse takes 40+ years to happen, and involves unemployment going to 100%:In any case, it is clearly apparent that nowhere in this paper - or in any other paper that I can find - does Keen present a model whose output bears even a passing resemblance to the crisis we experienced in the late 2000s. (As an aside, note that many models, including a simple neoclassical Ramsey model, have equilibria in which the economy collapses completely. Building such a model is very very easy. But complete economic collapses - total and permanent cessations of economic activity - haven't yet been seen in the real world...ever.)Therefore, we can conclude that there is no Steve Keen model that predicted the recession and long stagnation that we've experienced. And in fact, there does not seem to be a "Post-Keynesian model" whose features closely resemble the financial crises and recessions that we see in the real world.
So did Steve Keen himself warn in the early or mid 2000s of the impending possibility of an economic collapse? He claims that he did warn of an "impending global recession" in 2005 (see also here). I cannot find any actual writings by Keen from 2005, but I will take him at his word, since if he had made this up, I'm sure that his fellow Aussies would quickly tar and feather him for it. (If you have links to the 2005 prediction, please post them in the comments section.)
So Steve Keen presumably did warn in 2005 that a global recession was coming. This means that, counting his prediction of an imminent Australian crash, he has a 50% success rate. Remember that, according to Bayes' Theorem, the predictions of someone with an unconditional 50% success rate (i.e., coin flips) convey no information.
But is that his true success rate? After all, how many earlier predictions of imminent global recession has Keen made, that did not materialize? According to this website, Keen was predicting an imminent global recession as early as 1995. It was 12 or 13 years before his prediction came true; this long time lag makes the prediction a bit less impressive, since someone who in 1933 predicted a global recession - which did come, 80 years later - would nevertheless now be seen as having