This paper develops a theory of capital allocation in financial intermediaries where the cost of “risk capital” is a critical consideration. The implication for capital budgeting is that financial firms should use a modified NPV rule in which projects are valued by calculating the NPV of cash flows using marketdetermined discount rates and then subtracting a deadweight cost of capital that reflects the project's marginal contribution to firm-wide risk.
By taking account of deadweight costs—mainly monitoring and moral hazard costs associated with having too little equity capital as well as “free cash flow” agency costs and higher taxes associated with having too much—the capital allocation model predicts that financial firms will diversify across businesses with similar deadweight costs. Such diversification reduces the cost of risk capital for the individual businesses, thereby creating more profitable investment opportunities at the margin and enabling the businesses to operate on a larger scale. The authors note that their model has similarities to but also important differences from the standard applications of RAROC models.