The better argument for the deterministic case is that the present recession is NOT a business cycle at all, and neither was the Great Depression. (There aren't excess inventories of unsold goods, for example.) Rather, the present is an extraordinary recession caused by collapses in the financial system. Very few recessions are associated with general collapses of the financial sector. There does seem to be good reason to believe that financial system collapses have a high probability of resulting in economic decline. However, there is a lower correlation between asset bubble collapse and financial system collapse. So, without more research it is difficult to make deterministic claims about bubbles and unemployment, which is what I think you're trying to imply.
What is the conventional description of credit in the economy?
That credit has a causal relationship with this, and not just a symptomatic one, seems harder to support, at least with existing research.
Is that because there is no research on the topic, or because the research that there is doesn't support it?
The view I have summarised above is unconventional, but it was expounded by a well-known economist 100 years ago. As I am not too familiar with the academic literature, may I ask you if you know of some contemporary heterodoc economists who might agree with the view I proposed rather than with the conventional one which, if your summary is fair, seems to postulate that credit is incidental to the business cycle and not even part of a feedback loop? En un viejo país ineficiente, algo así como España entre dos guerras civiles, poseer una casa y poca hacienda y memoria ninguna. -- Gil de Biedma
