Its become a commonplace to simply blame the credit crunch on "stupid, greedy bankers". The trouble is, suppose you were a smart, frugal banker five years ago. Your exceptional brains let you see that subprime self-certified mortgages were a bad idea, and therefore anything built on them was clearly going to collapse. Therefore you weren't going to invest in that part of the market.
The trouble is, you would have had years of below-average results. Your clients and employers would be looking at your competitors and pointing out how bad your results were. Even if your clients were prepared to listen to your explanations, many are under a legal obligation to maximise their investment returns, and their customers will be less sophisticated and correspondingly less willing to listen to complicated explanations about why their pension is so much less than their neighbours.
So you get removed from your job, and someone else is put in who is willing to do what it takes to deliver market returns.
Looked at from an abstract point of view the game resembles a "Tragedy of the Commons". A banker who gets good returns while taking hidden risks is like the commoner who puts an extra cow on the common pasture. He gets richer while all his neigbours get a little poorer. So everyone else is forced to do likewise, even though everyone can see that collectively this is going to lead to ruin. And so the game goes.
The traditional solutions to the Tragedy of the Commons are:
- Property rights. Divide up the commons into individual plots and allocate them to the commoners. Failing that, give each commoner a tradeable right to put exactly one cow on the commons.
- Regulation. Make a law that each person can only put one cow on the commons.
So without this, what can we do to prevent the next big bust? It doesn't look like there is anything. As memories of this bust fade and the people who experienced it retire, a new generation of bankers will come along with a new ingenious method for hiding risk, and once again bad banking will drive out the good until the whole thing collapses once more.