Option Pricing and Replication with Transactions Costs

Transactions costs invalidate the Black-Scholes arbitrage argument for option pricing, since continuous revision implies infinite trading. Discrete revision using Black-Scholes deltas generates errors which are correlated with the market, and do not approach zero with more frequent revision when transactions costs are included. This paper develops a modified option replicating strategy which depends on the size of transactions costs and the frequency of revision. Hedging errors are uncorrelated with the market and approach zero with more frequent revision. The technique permits calculation of the transactions costs of option replication and provides bounds on option prices.     

Optimal Capital Structure,Endogenous Bankruptcy,and the Term Structure of Credit Spreads

This article examines the optimal capital structure of a firm that can choose both the amount and maturity of its debt. Bankruptcy is determined endogenously rather than by the imposition of a positive net worth condition or by a cash flow constraint. The results extend Leland's (1994a) closed-form results to a much richer class of possible debt structures and permit study of the optimal maturity of debt as well as the optimal amount of debt. The model predicts leverage, credit spreads, default rates, and writedowns, which accord quite closely with historical averages. While short term debt does not exploit tax benefits as completely as long term debt, it is more likely to provide incentive compatibility between debt holders and equity holders. Short term debt reduces or eliminates “asset substitution” agency costs. The tax advantage of debt must be balanced against bankruptcy and agency costs in determining the optimal maturity of the capital structure. The model predicts differently shaped term structures of credit spreads for different levels of risk. These term structures are similar to those found empirically by Sarig and Warga (1989). Our results have important implications for bond portfolio management. In general, Macaulay duration dramatically overstates true duration of risky debt, which may be negative for “junk” bonds. Furthermore, the “convexity” of bond prices can become “concavity.”     

Symposium on Public Policy Issues in Finance

The thesis of this symposium, organized by James Bicksler, was that while finance theory will surely inform practitioners, it seems appropriate to pay some attention to the opposite flow: practitioners can inform theory. Contributors include a distinguished group of practitioners with extensive backgrounds in economics, and economists with extensive public policy experience: Martin Feldstein, Robert Glauber, David Mullins, and Steven Wallman. Their topics range from privatizing social security, to managing market crashes, to the regulatory agency cost problem, to regulatory constraints in a technologically advanced world.     

Corporate Debt Value,Bond Covenants,and Optimal Capital Structure

This article examines corporate debt values and capital structure in a unified analytical framework. It derives closed-form results for the value of long-term risky debt and yield spreads, and for optimal capital structure, when firm asset value follows a diffusion process with constant volatility. Debt values and optimal leverage are explicitly linked to firm risk, taxes, bankruptcy costs, risk-free interest rates, payout rates, and bond covenants. The results elucidate the different behavior of junk bonds versus investment-grade bonds, and aspects of asset substitution, debt repurchase, and debt renegotiation.     

Event Risk: An Analysis of Losses to Bondholders and “Super Poison Put” Bond Covenants

Ten percent of the investment-grade industrial bonds that were associated with major capital restructurings between 1983 and 1988 had already been downgraded to speculative grade as of August 1989. In response to these downgrades, and the corresponding wealth losses for bondholders, over 40 percent of recently issued investment-grade industrial bonds are protected from this type of “event risk” by virtue of specialized covenants. These event-risk convenants may have initially reduced interest costs for borrowers by roughly 20 to 30 basis points. However, the magnitude of the effect appears to have declined along with the general decline in corporate restructurings.     

Does the Liquidity of a Debt Issue Increase with Its Size? Evidence from the Corporate Bond and Medium-Term Note Markets

To investigate the liquidity of large issues, this study tests for yield differences between corporate bonds and medium-term notes (MTNs). In the sample, MTNs have an average issue size of $4 million, compared with $265 million for bonds. Among MTNs that have the same issuance date, the same maturity date, and the same corporate issuer, we find no relation between size and yields. Moreover, bonds and MTNs have statistically equivalent yields. Thus, rather than suggesting that large issues have greater liquidity, these findings indicate that large and small securities issued by the same borrower are close substitutes.     

The Effect of a Rating Downgrade on Outstanding Commercial Paper

Diamond (1991) argues that a firm's reputation determines whether it borrows directly or through an intermediary. We test the Diamond model by examining the quantity response of commercial paper issued by bank holding companies to a rating downgrade. From 1986 to 1991, cumulative abnormal declines averaged 6.69 percent in the first two weeks after the downgrade and 11.05 percent in the subsequent 12 weeks. In contrast to commercial paper issued by bank holding companies, large CDs issued by affiliated banks did not change significantly in the period around a downgrade, suggesting that deposit insurance may have removed market discipline from the CD market.