A blog on financial markets and their regulation
Bank deposits without those exotic swaptions
February 4, 2015Posted by on
Yesterday, the Reserve Bank of India did retail depositors a favour: it announced that it would allow banks to offer “non-callable deposits”. Currently, retail deposits are callable (depositors have the facility of premature withdrawal).
Why can the facility of premature withdrawal be a bad thing for retail depositors? It would clearly be a good thing if the facility came free. But in a free market, it would be priced. The facility of premature withdrawal is an embedded American-style swaption and a callable deposit is just a non callable deposit bundled with that swaption whether the depositor wants that bundle or not. You pay for the swaption whether you need it or not.
Most depositors would not exercise that swaption optimally for the simple reason that optimal exercise is a difficult optimization problem to solve. Fifteen years ago, Longstaff, Santa-Clara and Schwartz wrote a paper showing that Wall Street firms were losing billions of dollars because they were using over simplified (single factor) models to exercise American-style swaptions (“Throwing away a billion dollars: The cost of suboptimal exercise strategies in the swaptions market.”, Journal of Financial Economics 62.1 (2001): 39-66.). Even those simplified (single factor) models would be far beyond the reach of most retail depositors. It is safe to assume that almost all retail depositors behave suboptimally in exercising their premature withdrawal option.
In a competitive market, the callable deposits would be priced using a behavioural exercise model and not an optimal exercise strategy. Still the problem remains. Some retail depositors would exercise their swaptions better than others. A significant fraction might just ignore the swaption unless they have a liquidity need to withdraw the deposits. These ignorant depositors would subsidize the smarter depositors who exercise it frequently (though still suboptimally). And it makes no sense at all for the regulator to force this bad product on all depositors.
Post global financial crisis, there is a push towards plain vanilla products. The non callable deposit is a plain vanilla product. The current callable version is a toxic/exotic derivative.