Economic stability under alternative banking systems: Theory and policy

In this paper we show in a thought experiment that in an economy where i) investors hold rational expectations, ii) output is generated by a linear homogeneous production function, and iii) real investment is allocated across sectors according to the CAPM, a fractional reserve banking system is not Pareto efficient and amplifies the business cycle. In developing these results we show that these three well known propositions in economics also imply a new view of the business cycle, one where the business cycle is described in terms of the dispersion of an ex-ante probability distribution. The policy implication of this analysis is that bank regulation should go further than the Volcker rule or the Vickers commission proposal by restricting bank investments to currency and deposit accounts on the central bank. Nonbank financial institutions should then carry out the financial intermediation function now carried out by banks. The paper proposes that post office banking perhaps augmented with blockchain technology sometime in the future is one way to implement the transition from fractional reserve banking to full reserve banking. While little academic work has been done on full reserve banking in the aftermath of the Great Crisis, it is interesting to note that it is part of banking reform proposals now (July 2016) before the parliament in Iceland and a special national referendum in Switzerland.