Chapter 10, Problem 3TCL

CALCULATING 3M’s COST OF CAPITAL

In this chapter, we described how to estimate a company’s WACC, which is the weighted average of its costs of debt, preferred stock, and common equity. Most of the data we need to do this can be found from various data sources on the Internet. Here we walk through the steps used to calculate Minnesota Mining & Manufacturing’s (MMM) WACC.

3. Next, we need to calculate MMM’s cost of debt. We can use different approaches to estimate it. One approach is to take the company’s interest expense and divide it by total debt (which is the sum of short-term debt and long-term debt). This approach only works if the historical cost of debt equals the yield to maturity in today’s market (i.e., if MMM’s outstanding bonds are trading at close to par). This approach may produce misleading estimates in years in which MMM issues a significant amount of new debt. For example, if a company issues a great deal of debt at the end of the year, the full amount of debt will appear on the year-end balance sheet, yet we still may not see a sharp increase in annual interest expense because the debt was outstanding for only a small portion of the entire year. When this situation occurs, the estimated cost of debt will likely understate the true cost of debt. Another approach is to try to find this number in the notes to the company’s annual report by accessing the company’s home page and its Investor Relations section. Alternatively, you can go to other external sources, such as bondsonline.com, for corporate bond spreads, which can be used to find estimates of the cost of debt. Remember that you need the after-tax cost of debt to calculate a firm’s WACC, so you will need MMM’s tax rate (which has averaged around 30% in recent years). What is your estimate of MMM’s after-tax cost of debt?