现代资本结构理论

自Modigliani和Miller提出MM理论以来,资本结构问题一直是理论界和实务界关注的焦点.本文从MM理论及其修正--基于税差的分析、基于权衡理论的资本结构理论、信息不对称条件下的资本结构理论、资本结构的实证研究四个方面阐述了自20世纪50年代以来资本结构理论的发展和研究成果,试图为我国学者开展资本结构研究提供借鉴.     

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.     

The expectations hypothesis of the term structure when interest rates are close to zero

In an economy where cash can be stored costlessly in nominal terms, the nominal interest rate is bounded below by zero. This paper derives the implications of this non-negativity constraint for the term structure and shows that it induces a nonlinear and convex relation between short- and long-term interest rates. The long-term rate responds asymmetrically to changes in the short-term rate, and by less than that is predicted by the benchmark linear model. In particular, a decrease in the short-term rate produces a smaller response in the long-term rate than an increase of the same magnitude. The empirical predictions of the model are examined using data from Japan.     

Generic pricing of FX,inflation and stock options under stochastic interest rates and stochastic volatility

We consider the pricing of FX, inflation and stock options under stochastic interest rates and stochastic volatility, for which we use a generic multi-currency framework. We allow for a general correlation structure between the drivers of the volatility, the inflation index, the domestic (nominal) and the foreign (real) rates. Having the flexibility to correlate the underlying FX/inflation/stock index with both stochastic volatility and stochastic interest rates yields a realistic model that is of practical importance for the pricing and hedging of options with a long-term exposure. We derive explicit valuation formulas for various securities, such as vanilla call/put options, forward starting options, inflation-indexed swaps and inflation caps/floors. These vanilla derivatives can be valued in closed form under Schöbel and Zhu [Eur. Finance Rev., 1999, 4, 23–46] stochastic volatility, whereas we devise an (Monte Carlo) approximation in the form of a very effective control variate for the general Heston [Rev. Financial Stud., 1993, 6, 327–343] model. Finally, we investigate the quality of this approximation numerically and consider a calibration example to FX and inflation market data.     

One Approach to Dual Randomness in Life Insurance

Abstract

1. The Unnatural Hypothesis of a Constant Rate of Interest

There are loan contracts which assume a constant interest during several years and thereafter payment of the amount borrowed, but nowadays clauses are as a rule admitted giving the debtor right of conversion or repayment after a certain period, generally ten years. Low interest loans can be considered as perpetuities from a practical point of view, as long as no possibility is meant to exist that the market rate will fall under their nominal rate. Such a loan—as e.g. Consols—with the nominal rate i ₀ ought to be valued at a discount if the market rate is higher, say i > i ₀, the value being equal to the fraction i ₀ : i. But constant rates are no rule in practice.     

Inflation,wealth and interest rates in an intertemporal optimizing model

This paper analyzes the relationship between the growth of the money supply and capital accumulation in a monetary optimizing model. Under certain conditions we show that a large intertemporal elasticity of substitution makes the nominal rates of interest undershoot its long-term value, that a low elasticity gives rise to overshooting, while a unitary elasticity is shown to make the nominal rate of interest a constant. These considerations plus explicit attention paid to the income and substitution effects induced by the changes in the nominal rates of interest provide us with an understanding of the correlation between growth of money and capital accumulation.     

When are preferred shares preferred? Theory and empirical evidence

This paper demonstrates that preferred stock may arise as an optimal security in a tax-induced equilibrium. This result is driven by graduated tax schedules and by uncertainty. In a more general sense, our results can be interpreted as a template for including any security with a different tax treatment in a firm's capital structure. The first part of the paper demonstrates that the Miller equilibrium framework can accommodate more than two securities if different investor classes are taxed differently on each security and the tax schedule for each investor group is upward sloping. We then simplify the tax schedule, but introduce uncertainty, which implies the possibility of bankruptcy and the possible loss of tax shelters. The interaction of tax rates and seniority now affects the contribution of each security to after-tax firm value, as in some states the firm may not be able to pay either interest (or dividends) or even principal to its various claimholders. It is shown why and how these features, i.e. the various tax rates and seniority, determine the financing equilibrium, which is obtained by equating the expected marginal tax benefit of all securities. We demonstrate that non-profitable firms will tend to issue preferred shares whereas profitable firms will not find preferred stock advantageous in our framework. Comparative statics with respect to various tax rates are derived as well. These predictions are tested using a large sample of firms for the last 25 years. The empirical testing broadly confirms the theoretical predictions.     

Nominal Interest Rates and the News

This paper provides new estimates of the impact of monetary policy actions and macroeconomic news on the term structure of nominal interest rates. The key novelty is to parsimoniously capture the impact of news on all interest rates using a simple no‐arbitrage model. The different types of news are analyzed in a common framework by recognizing their heterogeneity, which allows for a systematic comparison of their effects. This approach leads to novel empirical findings. First, monetary policy causes a substantial amount of volatility in both short‐term and long‐term interest rates. Second, macroeconomic data surprises have small and mostly insignificant effects on the long end of the term structure. Third, the term‐structure response to macroeconomic news is consistent with considerable interest‐rate smoothing by the Federal Reserve. Fourth, monetary policy surprises are multidimensional while macroeconomic surprises are one‐dimensional.     

The cost of capital and optimal financing policy in a dynamic setting

This paper revisits the Modigliani–Miller propositions on the optimal financing policy and cost of capital in a dynamic setting. In an environment without taxes and bankruptcy costs, the results are generally consistent with the Modigliani–Miller Propositions 1 and 2. However, the first proposition should be presented and interpreted more carefully, as given firm characteristics, there is only one optimal capital structure. Thus, a firm’s capital structure is relevant. A relaxation of assumptions about either taxes or bankruptcy costs leads to conclusions that are generally different from those in Modigliani and Miller (1958). The model predicts that leverage and sales-to-capital ratios decrease but firm size and capital stock increase with the subjective discount factor of the firm’s manager if there are taxes and bankruptcy costs. The empirical analysis supports these predictions.     

Traffic light options

This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic light solvency stress test system introduced by the Danish Financial Supervisory Authority (DFSA) in June 2001. This monitoring system requires L&P companies to submit regular reports documenting the sensitivity of the companies’ base capital to certain pre-defined market shocks – the red and yellow light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden’s FSA implemented a traffic light system in January 2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black–Scholes/Hull–White model to describe stock market and interest rate dynamics, and analyze the traffic light option in this framework.     

On the Relevance of Debt Maturity Structure

In this paper, we present a tax-induced framework to analyze debt maturity problems. We show that under some modifications of the existing U.S. tax code, debt maturity is irrelevant even in the presence of taxes and bankruptcy costs that yield an optimal capital structure. If this restrictive structure is relaxed, and assuming the Miller [15] equilibrium does not prevail, tax reasons would usually imply the existence of an optimal debt maturity structure. If there exists a gain from leverage, then an increasing term structure of interest rates, adjusted for default risk, results in long-term debt being optimal. A decreasing term structure, under similar circumstances, renders short-term debt optimal. In the absence of agency costs, a Miller [15]-type result emerges at equilibrium and irrelevance prevails. We also argue that agency costs could again reverse the irrelevance and imply a firm-specific optimal debt maturity structure.     

Stochastic interest rate modelling using a single or multiple curves: an empirical performance analysis of the Lévy forward price model

In current financial markets negative interest rates have become rather persistent, while in theory it is often common practice to discard such rates as incredible and irrelevant. However, from a risk management perspective, it is crucially important to financial institutions to properly account for this phenomenon in their Asset Liability Management (ALM) studies. In this paper, we develop a coherent framework on how to best incorporate negative interest rates in these studies through a single curve stochastic term structure model and compare it to its multiple curve analogue. It turns out that, from the wide range of available single curve models, especially the Lévy Forward Price model (LFPM) of Eberlein and Özkan [The Lévy LIBOR model. Financ. Stoch., 2005, 9, 327–348] seems appropriate for ALM purposes. This paper describes an optimisation routine for calibrating this LFPM under the risk-neutral measure in both the single and multiple curve framework to the market prices of interest rate caplets with different strike rates, maturities and tenors. In addition, an empirical performance analysis is made of the single and multiple curve LFPM, where we include four deterministic volatility specifications and provide an explicit parametrisation of a piecewise homogeneity restriction with both deterministic and random breakpoints. This comparative analysis indicates that both the single and multiple curve LFPM is best adopted with the Linear-Exponential Volatility (LEV) specification and that deterministic breakpoints should be included, rather than random breakpoints.     

A Liquidity-Based Resolution of the Uncovered Interest Parity Puzzle

A new monetary theory is set out to resolve the “uncovered interest parity (UIP)” puzzle. It explores the possibility that liquidity properties of money and nominal bonds can account for the puzzle. A key concept in our model is that nominal bonds carry liquidity premia. We show that the UIP can fail to hold under the economic environment where collateral pledgeability and/or liquidity of nominal bonds and/or collateralized credit-based transactions are relatively bigger. Our liquidity-based theory can help understanding many empirical observations that risk-based explanations find difficult to reconcile with.     

Do Personal Taxes Destroy Tax Shields? A Critique to Miller’s (1977) Proposal

We discuss the relevance of personal taxes on tax shields. Interest and taxes are the basis for defining an optimal capital structure. When personal taxes are greater than or equal to TS, an optimal capital structure does not exist.

We suggest that the approach proposed by Miller (1977) might understate the effect of personal taxes in the net TS and/or its associated net value. We consider the irrelevance of personal taxes on interest received by debtholders on the value of TS earned by the firm on interest paid. We conclude that Miller’s approach might be wrong and has some inconsistencies.     

Are Indexed Bonds Really Inflation Proof? A Model of Real and Nominal Term Structures when Money has Real Effects

This paper studies the general behavior of the nominal and real term structures of interest rates in a general equilibrium framework. A central bank is introduced in the model as an agent facing a tradeoff between inflation and output and choosing a monetary policy variable. Prices and output are jointly determined in our model endogenously. Two multi-factor nominal and real term structure models are given as examples to illustrate the general model. In our economies, inflation indexed bonds are not completely inflation proof, but are still subject to the influence of inflation uncertainties. The models offer us an empirical framework that can be studied with indexed bond data and nominal bond data together in a single estimation.     

On the Equivalence between the APV and the wacc Approach in a Growing Leveraged Firm

While in a steady state framework the choice between the wacc approach ( Modigliani‐Miller, 1963 ) and the adjusted present value (APV) approach ( Myers, 1974 ) is irrelevant since the two approaches provide the same result, however, in a growing firm context the wacc equation seems to be inconsistent with the APV result. In this paper we propose a simple model to evaluate the tax savings in a growing firm in order to show under which assumptions the two approaches lead to the same results. We demonstrate that the use of the wacc model in a steady‐growth scenario gives rise to some unusual assumptions with regard to the discount rates to be used in calculating tax shields. We show that the widely used wacc formula, if used, as it is in most cases, in a growth context, implies that a) debt tax shield related to already existing debt are discounted using k_d; b) debt tax shield related to new debt, due to company's growth, are discounted, according to a mixed procedure, using both k_u and k_d. We discuss the inconsistency of such a discounting procedure and the preferred features of the APV approach.     

Do Credit Spreads Reflect Stationary Leverage Ratios?

Most structural models of default preclude the firm from altering its capital structure. In practice, firms adjust outstanding debt levels in response to changes in firm value, thus generating mean-reverting leverage ratios. We propose a structural model of default with stochastic interest rates that captures this mean reversion. Our model generates credit spreads that are larger for low-leverage firms, and less sensitive to changes in firm value, both of which are more consistent with empirical findings than predictions of extant models. Further, the term structure of credit spreads can be upward sloping for speculative-grade debt, consistent with recent empirical findings.     

Visual rhetoric and the case of intellectual capital

Visual images abound in accounting-related media and are powerful tools for communicating messages regarding all aspects of organisations. This is particularly important in the case of intellectual capital, where a deficient accounting framework for intangibles leads stakeholders to seek enlightenment beyond the financial statements. The central contribution of the work presented here is the development of theory to guide the interpretation of visual rhetoric in pictures and photographs. Within an over-arching framework of Barthesian visual semiotics, a model of visual rhetoric and repetition is developed by reference to the work of Durand and others. Four types of visual repetition are identified: identity, similarity, accumulation and series. In the light of this model, illustrative examples of visual images from annual reports are analysed to indicate how visual rhetoric contributes to the communication of intellectual capital.     

PRICING CURRENCY OPTIONS UNDER STOCHASTIC INTEREST RATES AND JUMP‐DIFFUSION PROCESSES

We investigate the effects of stochastic interest rates and jumps in the spot exchange rate on the pricing of currency futures, forwards, and futures options. The proposed model extends Bates's model by allowing both the domestic and foreign interest rates to move around randomly, in a generalized Vasicek term‐structure framework. Numerical examples show that the model prices of European currency futures options are similar to those given by Bates's and Black's models in the absence of jumps and when the volatilities of the domestic and foreign interest rates and futures price are negligible. Changes in these volatilities affect the futures options prices. Bates's and Black's models underprice the European currency futures options in both the presence and the absence of jumps. The mispricing increases with the volatilities of interest rates and futures prices. JEL classification: G13     

Risk-neutral and actual default probabilities with an endogenous bankruptcy jump-diffusion model

This paper focuses on historical and risk-neutral default probabilities in a structural model, when the firm assets dynamics are modeled by a double exponential jump diffusion process. Relying on the Leland [(1994a) Journal of Finance, 49, 1213–1252; (1994b) Bond prices, yield spreads, and optimal capital structure with default risk. Working paper no. 240, IBER, University of California, Berkeley] or Leland and Toft [(1996) Journal of Finance, 51(3), 987–1019] endogenous structural approaches, as formalized by Hilberink and Rogers [(2002) Finance and Stochastics, 6(2), 237–263], this article gives a coherent construction of historical default probabilities. The risk-neutral world where evolve the firm assets, modeled by a class of geometric Lévy processes, is constructed based on the Esscher measure, yielding useful and new analytical relations between historical and risk-neutral probabilities. We do a complete numerical analysis of the predictions of our framework, and compare these predictions with actual data. In particular, this new framework displays an enhanced predictive power w.r.t. current Gaussian endogenous structural models.