We rationalize the organization of US banking groups into a holding company with subsidiaries – instead of branches or stand-alone units – subject to regulatory provisions of the ”source-of strength” type. We show that their value increases with debt diversity among affiliates and with complexity, as measured by the number of subsidiaries. Regulatory interventions that are aimed at ring fencing reduce (increase) the shareholder value, whenever the Governmental leniency to bailout is low (high). Branches become more valuable when there is no full commitment to internal rescue and Government bailout occurs with certainty.

The presence of any friction in financial markets qualitatively changes the nature of the optimization problem faced by an investor. It requires one to either act or do nothing, an issue which, of course, does not arise in frictionless situations. The investor considered here accumulates wealth without consuming until some terminal point in time when he consumes all. His objective is to maximize the expected utility derived from that terminal consumption. We postpone the terminal point far into the future to obtain a stationary portfolio rule. The portfolio policy is in the form of two control barriers between which portfolio proportions are allowed to fluctuate. We show how to calculate them.