What is important to emphasize again, at this juncture, is that the fact
that there is no clear separation between financial markets and the ‘real
economy’ produced many of the problems in the banking sector. This
is something which, almost by definition, does not show up, or rather is
absent from, most macroeconomic models. In the evolution of the drying
up of the credit market, an important role was played by major corporations
drawing on existing credit lines and thereby exacerbating the situation.
As Ivashina and Scharfstein (2010) explain, these credit-line
drawdowns were part of the ‘run’ on banks that occurred at the height
of the crisis. Unlike old-style bank runs, instigated by uninsured depositors
when there was no deposit insurance, this bank run was instigated by
short-term creditors, counterparties, and borrowers who were concerned
about the liquidity and solvency of the banking sector. In other words,
concerns about the financial sector led actors in the economy to behave in
a way which reinforced the crisis. So, the evolution of the crisis involved in
a crucial way, the interdependence of the real and the financial economies. To explain this evolution, the question is not to see how the economy
moved away from, and might then return to, an equilibrium in the classic
sense, it is rather to understand what sort of framework it had developed
to achieve all of the coordination and interdependence that we did
observe. Then, and more importantly, we have to explain how that
self-organization and the contagious reaction of the components could
lead to a major phase change. There are therefore two levels on which
to argue. On the one hand, we would like to explain how all the agents in
the economy come to coordinate their daily activities in a relatively stable
fashion even though this may not correspond to an equilibrium in the
standard sense. On the other hand, we have to explain how a system
functioning in this way, once again with no central authority to control
it, can suddenly evolve into a crisis?