Some firms that are under or over levered may choose to not change their debt
ratios to the optimal. This may arise either because they do not share the objective of
maximizing firm value that underlies optimal debt ratios, or because they feel that the
costs of moving to the optimal outweigh the benefits. Firms that do decide to change their
financing mixes can change either gradually or quickly. Firms are much more likely to
change their financing mixes quickly if external pressure is brought to bear on the firm.
For under levered firms, the pressure takes the form of hostile acquisitions, whereas for
over levered firms, the threat is default and bankruptcy. Firms that are not under external
pressure for change have the luxury of changing towards their optimal debt ratios
gradually.
Firms can change their debt ratios in four ways. They can recapitalize existing
investments, using new debt to reduce equity or new equity to retire debt. They can divest
existing assets, and use the cash to reduce equity or retire debt. They can invest in new
projects, and finance these investments disproportionately with debt or equity. Finally,
they can increase or decrease the proportion of their earnings that are returned to
stockholders, in the form of dividends or stock buybacks. To decide between these
alternatives, firms have to consider how quickly they need to change their debt ratios, the
quality of the new investments they have and the marketability of existing investments.
In the final section, we examine how firms choose between financing vehicles.
Matching cash flows on financing to the cash flows on assets reduces default risk and
increases the debt capacity of firms. Applying this principle, long-term assets should be
financed with long term debt, assets with cash flows that move with inflation should be
financed with floating rate debt, assets with cash flows in a foreign currency should be
financed with debt in the same currency, and assets with growing cash flows should be
financed with convertible debt. This matching can be done intuitively, by looking at a
typical project, or can be based upon historical data. Changes in operating income and
value can be regressed against changes in macroeconomic variables to measure the
sensitivity of the firm to these variable. This can then be used to design the optimal
financing vehicle for the firm. Once we identified the right financing vehicle, we have to
make sure that we preserve the tax advantages of debt, and keep equity research analysts
and ratings agencies happy.