Debt Valuation and the Cost of Capital

Introduction

Firms rarely finance capital projects by equity alone. They utilize long and short term funds from a variety of sources at a variety of costs. No one source is free. Moreover, as the following table reveals, some have an explicit cost but others only an implicit or opportunity cost. For example the marginal cost of earnings retained for new investment is measured by the current return foregone by shareholders, whereas debt is sourced at an explicit market rate of interest. Explicit or not, in order to establish the overall cost of capital as a project discount rate, management must first identify the current (marginal) cost of each type of capital employed (debt, as well as equity).The component costs must then combined to form the marginal, weighted average cost of capital (WACC).

To understand the conceptual derivation of WACC (which we shall consider in Chapter Seven) let us analyse the value and cost of the most significant alternative to equity as an external source of finance, namely corporate borrowing in the form of debentures (or corporate bonds and loan stock to use American parlance).

Capital Gearing (Leverage): An Introduction

Corporate borrowing is attractive to management because interest rates on debt are typically lower than the cost of equity. Debt-holders accept lower returns than shareholders because their investment is less risky. Unlike dividends, interest is guaranteed and a prior claim on profits. As creditors, debt-holders are also paid before shareholders from the sale of assets in the event of liquidation. Interest payments on debt also qualify for corporate tax relief, which does not apply to dividends, thereby reducing their real cost to the firm.

The introduction of borrowing into the corporate financial structure, termed capital gearing or leverage, can therefore lower the overall return (cut-off rate) that management need to earn on new investments relative to all-equity funding. Consequently, the expected NPV of geared projects should rise with a fall in their discount rates, producing a corresponding increase corporate wealth.

The Value of Debt Capital and Capital Cost

As marketable securities, the principles of loan valuation are similar to those for equity but less problematical. Stock is issued above, below or at par value depending on economic conditions. However, the annual cash return is known from the outset. It always equals a specific rate of interest relative to par value (termed the coupon rate or nominal yield). The stock's life might also be specified in advance with a guaranteed capital repayment (i.e. redeemable as opposed to irredeemable debt). Ignoring tax for the moment:

- The current price of any debenture (bond) is determined by a summation of future interest payments, plus the redemption price (if applicable) all discounted back to a present value.

- The annual cost of corporate debt or yield (to redemption if applicable) is the discount rate that equates current price to these expected future cash flows, namely their Internal Rate of Return (IRR).

In the case of irredeemable debentures, about to be issued or subsequently trading at par, the market price and IRR obviously equal the par value and coupon rate respectively. However, if price differs from par value, either at issue or when the debt is later traded, the IRR no longer equals the coupon rate. To see why, let us define the price of debt (P0) at any point in time.

where: I = interest (the coupon rate expressed in money terms) received per annum in perpetuity Kd = the company's annual cost of debt defined as an IRR percentage.

Since the annual interest payment is fixed in perpetuity, Equation (1) simplifies to the familiar valuation formula for a level annuity: interest divided by current market price:

(2) P0 = I / Kd

If we rearrange terms, the cost of debt equals the investment's IRR defined as the annual money interest divided by current market price:

(3) Kd = I / P0

And because interest (I) is constant year on year, it follows that if Po rises (or falls) then Kd must fall (or rise) proportionately.

Turning to redeemable stock, the nominal return to debt-holders in the year of redemption will be uplifted by the redemption price payable. Thus, when debt is issued or whenever investors trade debentures, the current yield (Kd) is found by solving for the IRR in the following finite equation.

rewritten as follows:

where: n = the number of periods to redemption, Pn = the redemption value at time period n.

Irrespective of whether debt is redeemable, irredeemable, currently traded or about to be issued:

- The cost of capital (Kd) always equals an internal rate of return (IRR).

- The IRR equates current price to the discounted future cash receipts that the loan stock produces.

- Only if the current price and redemption value (if any) equal the par value will the IRR equal the coupon rate (nominal yield).

If a debt issue has a coupon rate which is below the prevailing market rate of interest defined by its current IRR then by definition current market value (price) will be below par value and vice versa.

Activity 1

Use the previous equations to calculate current debt yields if a company issued:

- £100 irredeemable debentures with a 10 percent coupon rate

- £100 debentures with the same coupon rate, redeemable at par ten years hence

You may assume that in both cases, similar debentures currently trade below par at £90.00 (conventionally termed as £90 per cent).

What do these calculations mean to investors and corporate management?

Given current market conditions both £100 issues must be priced at £90 to ensure full subscription.

If irredeemable debentures are issued at £90 percent with a money coupon rate of £10 per annum, it follows from Equation (3) that the current yield or cost of debt:

Kd = £10 / £90 = 11.1% d

If redeemable ten year debt was issued at the same price with the same coupon rate, we must derive the current yield by solving for IRR using Equation (5).

Now the annual cost of debentures Kd is approximately 11.8%

For the investor, both debenture formulae perform the same functions as the equity models presented in Chapter Five. Even though interest is fixed and a redemption date may be specified, debentures can be traded at either a premium or a discount throughout their life. Thus, the current rate of interest, like an equity yield, is only a guide to the true return on life-time investment. In a world of uncertainty it can only be determined by incorporating the capital gain or loss retrospectively when the security is sold. In the case of redeemable debentures, held from issue through to redemption, this ex-post return calculation is termed the yield to maturity or redemption yield.

The current yield on debentures Kd therefore represents the return from holding the investment, rather than selling at its current market price. It is an implicit opportunity cost of capital, because it is the minimum return below which debenture holders could transfer their funds elsewhere for a market rate of interest of equivalent risk, (Fisher's Separation Theorem again).

For the company, a successful debenture issue must therefore match the risk-return profile (yield) of loan stock currently trading on the market. In an untaxed economy (more of which later) this rate of interest required by investors represents the company's marginal cost of capital for this fund source. As such, Kd is the relevant measure for assessing any new project financed by loan stock.

Returning to our previous Activity, if management wish to maximise corporate wealth using ENPV criteria then the 10 per cent coupon rate (nominal yield) is irrelevant. To be more precise, new projects should be financed by irredeemable debt at a "real" cost of 11.1 per cent discount rate, rather than redeemable debt with a cost of 11.8 per cent. Remember: the lower the discount rate, the higher the ENPV and vice versa. So at one extreme, a project discounted at the coupon rate might be accepted, whilst at the other, the redeemable rate signals rejection. Either way, corporate wealth is compromised; with a worst case scenario where the cash flows for a project's accepted using the coupon rate as a discount rate will not service debt, forcing the firm into liquidation.

To conclude, projects financed by debt (just like equity) should always be evaluated using a marginal cost of capital and not the nominal yield Only if the incremental return equals the current yield will the marginal cost of raising additional finance equal the current cost of capital in issue and attract investors.