An IFRS 2 and FASB 123 (R) Compatible Model for the Valuation of Employee Stock Options

In this paper, we show how employee stock options can be valued under the new reporting standards IFRS 2 and FASB 123 (revised) for share-based payments. Both standards require companies to expense employee stock options at fair value. We propose a new valuation model, referred to as Enhanced American model, that complies with the new standards and produces fair values often lower than those generated by traditional models such as the Black–Scholes model or the adjusted Black–Scholes model. We also provide a sensitivity analysis of model input parameters and analyze the impact of the parameters on the fair value of the option. The valuation of employee stock options requires an accurate estimation of the exercise behavior. We show how the exercise behavior can be modeled in a binomial tree and demonstrate the relevance of the input parameters in the calibration of the model to an estimated expected life of the option. JEL Classification G13, G30     

Employee Stock Options, Equity Valuation, and the Valuation of Option Grants Using a Warrant-Pricing Model

We investigate the use of a warrant‐pricing approach to incorporate employee stock options (ESOs) into equity valuation and to account for the dilutive effect of ESOs in the valuation of option grants for financial reporting purposes. Our valuation approach accounts for the jointly determined nature of ESO and shareholder values. The empirical results show that our stock price estimate exhibits lower prediction errors and higher explanatory powers for actual share price than does the traditional stock price estimate. We use our valuation approach to assess the implications of dilution on the fair‐value estimates of ESO grants. We find that the fair value is overstated by 6% if we ignore the dilutive feature of ESOs. Furthermore, this bias is larger for firms that are heavy users of ESOs, small, and R&D intensive, and for firms that have a broad‐based ESO compensation plan.     

The Cost of Employee Stock Option Grants: An Empirical Analysis

This study presents empirical evidence on the ex post costs of employee stock option (ESO) grants to issuing firms and examines whether the Black–Scholes [1973] model provides reasonable estimates of these values. Because there are no market prices for ESOs, the traditional avenues for testing option–pricing models are unavailable. This research relies instead on techniques from the economic forecasting literature, viewing model values as forecasts of the options' payoff. The theoretically appropriate rate at which to discount ESO payoffs is derived under the maintained hypothesis that the Black–Scholes model is valid. This rate is used in estimating ex post ESO costs at the time of grant, which are then compared with Black–Scholes estimates using Theil's [1966] tests of forecast rationality. Based on a sample of 966 ESO grants over 1963–1984, the results suggest that the Black–Scholes model, adjusted for concavity in the time to exercise using the Hemmer, Matsunaga, and Shevlin [1994] procedure, appears to provide reasonable estimates of ex post ESO costs for the average ESO grant. However, there is significant variability in the amount of model error on an individual grant basis.     

Smiles, Bid‐ask Spreads and Option Pricing

Given the evidence provided by Longstaff (1995), and Peña, Rubio and Serna (1999) a serious candidate to explain the pronounced pattern of volatility estimates across exercise prices might be related to liquidity costs. Using all calls and puts transacted between 16:00 and 16:45 on the Spanish IBEX‐35 index futures from January 1994 to October 1998 we extend previous papers to study the influence of liquidity costs, as proxied by the relative bid‐ask spread, on the pricing of options. Surprisingly, alternative parametric option pricing models incorporating the bid‐ask spread seem to perform poorly relative to Black‐Scholes.     

The Pricing of Risk and Sentiment: A Study of Executive Stock Options

Option pricing models accounting for illiquidity generally imply the options are valued at a discount to the Black‐Scholes value. Our model considers the role of sentiment, which offsets illiquidity. Using executive stock options and compensation data from 1992 to 2004 for S&P 1500 firms, we find that executives value employee stock options (ESOs) at a 48% premium to the Black‐Scholes value. These premia are explained by a sentiment level of 12% in risk‐adjusted, annualized return, suggesting a high level of executive overconfidence. Subjective value relates negatively to illiquidity and idiosyncratic risk, and positively to sentiment in all specifications, consistent with the offsetting roles of sentiment and risk aversion.     

Financial reporting for employee stock options: liabilities or equity?

This study seeks to determine whether employee stock options share key characteristics of liabilities or equity. Consistent with warrant pricing theory, we find that common equity risk and expected return are negatively associated with the extent to which a firm has outstanding employee stock options, which is opposite to the association for liabilities. We also find the following. (1) The association is positive for firms that reprice options and less negative for firms that have options with longer remaining terms to maturity, which indicates that some employee stock options have characteristics that make them more similar to liabilities. (2) Leverage measured based on treating options as equity has a stronger positive relation with common equity risk than leverage measured based on treating options as liabilities. (3) The sensitivity of employee stock option value to changes in asset value mirrors that of common equity value and is opposite to that of liability value. Also, we find that, unlike liabilities, employee stock options have substantially higher risk and expected return than common equity. Our findings are not consistent with classifying employee stock options as liabilities for financial reporting if classification were based on the directional association of a claim with common equity risk and expected return. Rather, our findings suggest the options act more like another type of equity.     

Non-marketability and the value of employee stock options

We adapt the Benninga et al. (2005) framework to value employee stock options (ESOs). The model quantifies non-diversification effects, is computationally simple, and provides an endogenous explanation of ESO early-exercise. Using a proprietary dataset of ESO exercise events we measure the non-marketability ESO discount. We find that the ESO value on the grant date is approximately 45% of a similar plain vanilla Black–Scholes value. The model is aligned with empirical findings of ESOs, gives an exercise boundary of ESOs and can serve as an approximation to the fair value estimation of share-based employee and executive compensation. Using the model we give a numerical measure of non-diversification in an imperfect market.     

Accelerated Vesting of Employee Stock Options in Anticipation of FAS 123-R

In December 2004, the Financial Accounting Standards Board (FASB) mandated the use of a fair value–based measurement attribute to value employee stock options (ESOs) via Financial Accounting Standard (FAS) 123-R. In anticipation of FAS 123-R, between March 2004 and November 2005, several firms accelerate the vesting of ESOs to avoid recognizing existing unvested ESO grants at fair value in future financial statements. We find that the likelihood of accelerated vesting is higher if (1) acceleration has a greater effect on future ESO compensation expense, especially related to underwater options, and (2) firms suffer greater agency problems, proxied by fewer blockholders, lower pension fund ownership, and top five officers holding a greater share of ESOs. We also find a negative stock price reaction around the announcement of the acceleration decision. Furthermore, stock returns are significantly negative before the new vesting dates and positive afterward, suggesting that vesting dates could have been backdated.     

Equity value,implied cost of equity and shareholders’ real options

This study investigates the effects of shareholders’ real options on (i) firm financial performance and (ii) estimations of the implied cost of equity. After measuring the equity value of steady‐state operations using the residual income model, and the abandonment and expansion options using the Black‐Scholes option pricing model, I find that firms with a large expansion (abandonment) option value experience better (worse) financial performance than those with a small such value. I also find that ignoring these options results in a downward bias in implied cost of equity estimates by an average of 1.23 percentage points.     

Is backdating executive stock options always costly to shareholders?

We use a binomial model to investigate the cost to shareholders of backdating employee stock option (ESO) grants to award in‐the‐money rather than at‐the‐money options to a manager. When the expected return of the stock underlying an ESO is sufficiently close to the risk‐free rate, a backdating arrangement can always be structured to simultaneously improve shareholders’ wealth and the manager's utility. The smaller the manager's non‐option wealth, personal income tax rate or risk tolerance, the more likely a backdating arrangement can be welfare improving.     

Cross-sectional tests of deterministic volatility functions

We study the cross-sectional performance of option pricing models in which the volatility of the underlying stock is a deterministic function of the stock price and time. For each date in our sample of FTSE 100 index option prices, we fit an implied binomial tree to the panel of all European style options with different strike prices and maturities and then examine how well this model prices a corresponding panel of American style options. We find that the implied binomial tree model performs no better than an ad-hoc procedure of smoothing Black–Scholes implied volatilities across strike prices and maturities. Our cross-sectional results complement the time-series findings of Dumas et al. [J. Finance 53 (1998) 2059].     

How Might Companies Value ESOs?

There has been a steady growth in the use of employee equity compensation plans, and in the use of executive stock options (ESOs) in particular, along with a rise in shareholder and public perceptions that the values of compensation plans are not always fully disclosed. The IFSA of Australia recently called for separate reporting in financial statements of numbers and values of ESOs. Companies, when negotiating employment contracts, frequently agree to compensate an executive if a share option plan is subsequently not approved by shareholders. These facts suggest that reporting the value of an ESO plan is a useful and important exercise. We outline a model for the valuation of ESOs typically issued by Australian listed companies and illustrate the application of the model with a case study.     

Real Investment Implications of Employee Stock Option Exercises

This paper examines a real cost of awarding employee stock options. Based on the observation that managers are extremely concerned about earnings-per-share dilution in equity related compensation, we predict and find that firms experiencing significant employee stock option (ESO) exercises shift resources away from real investments towards the repurchase of their own stocks. We further find weak evidence of a decline in subsequent firm performance (as measured by return on assets) for several years following the cut in discretionary investments as a result of stock option exercises, though this result is sensitive to the metric used to measure performance. Collectively, our findings indicate that ESO exercises potentially impose a real cost on the firm in terms of foregone investment opportunities.     

Valuing employee stock options under SFAS 123R using the Black–Scholes–Merton and lattice model approaches

In 2004, the Financial Accounting Standards Board (FASB) issued Statement of Financial Accounting Standard No. 123 (revised 2004), Share-Based Payments (SFAS 123R), requiring all entities to recognize as expense the fair value of stock options issued to employees for services provided. Because employee stock options cannot be traded publicly, their fair value must be estimated using a model, with the Black–Scholes–Merton (BSM) and lattice models being the most appropriate alternatives.This teaching note provides an overview of employee stock options, followed by a discussion of the BSM and lattice valuation models, including their application and limitations. A project which has been used in financial accounting courses is also presented. The conceptual discussion coupled with illustrated examples will help students enhance their understanding of fair value estimation of and accounting for employee stock options under the recently adopted SFAS 123R.     

Option Pricing under Stochastic Interest Rates: An Empirical Investigation

Using daily data of the Nikkei 225 index, call option prices and call money rates of the Japanese financial market,a comparison is made of the pricing performance of stock option pricing modelsunder several stochastic interest rate processes proposedby the existing term structure literature.The results show that (1) one option pricing modelunder a specific stochastic interest ratedoes not significantly outperformanother option pricing model under an alternative stochasticinterest rate, and (2) incorporating stochastic interest ratesinto stock option pricing does not contribute to the performanceimprovement of the original Black–Scholes pricing formula.     

ESO compensation: The roles of default risk, employee sentiment, and insider information

This paper derives a pricing model for employee stock options (ESO) that includes default risk and considers employee sentiment. Using ESO data from 1992 to 2004, the study finds that the average executive's subjective value is about 55% of the Black-Scholes value. Only employees who over-estimate firm returns (or insiders who know that the firm is under-valued) by about 10% per annum will prefer ESOs over cash compensation. Our model also shows that work incentives offered by ESOs may be far lower than those implied by Black-Scholes but that ESOs may induce less risk-taking behavior, contrary to typical moral hazard arguments. Findings may impact relevant accounting regulations as well as compensation decisions.     

Employee sentiment and stock option compensation

The use of equity-based compensation for rank-and-file employees is a puzzle. We analyze whether the popularity of option compensation may be driven by employee optimism, and show that optimism by itself is insufficient to make option compensation optimal. The crucial insight is that firms compete with financial markets as suppliers of equity to employees and that employees’ access to the equity market restricts firms’ ability to profit from employee optimism. Firms must be able to extract some of the implied rents even though employees can purchase company equity in the financial markets. Such rent extraction becomes feasible if employees prefer the stock options offered by firms to the equity offered by the market, or if the traded equity is overvalued. We provide empirical evidence that firms use broad-based option compensation when boundedly rational employees are likely to be excessively optimistic about company stock, and when employees are likely to strictly prefer options over stock.     

Repricing and employee stock option valuation

A repricing occurs when the issuing firm resets the strike price of an employee stock option (ESO). ESO repricings occur most frequently following a significant decline in the underlying stock price. Typically, the strike price is reset to the new stock price. We develop a new model for valuing ESOs with a repricing feature. Our valuation model is developed within a utility-maximizing framework that accounts for potentially multiple repricings, employee risk aversion, employee non-option wealth, the non-tradeability of ESOs, and the early exercise feature of ESOs. Simulations suggest that these factors can significantly affect ESO value.     

Generative Bayesian neural network model for risk-neutral pricing of American index options

Financial models with stochastic volatility or jumps play a critical role as alternative option pricing models for the classical Black–Scholes model, which have the ability to fit different market volatility structures. Recently, machine learning models have elicited considerable attention from researchers because of their improved prediction accuracy in pricing financial derivatives. We propose a generative Bayesian learning model that incorporates a prior reflecting a risk-neutral pricing structure to provide fair prices for the deep ITM and the deep OTM options that are rarely traded. We conduct a comprehensive empirical study to compare classical financial option models with machine learning models in terms of model estimation and prediction using S&P 100 American put options from 2003 to 2012. Results indicate that machine learning models demonstrate better prediction performance than the classical financial option models. Especially, we observe that the generative Bayesian neural network model demonstrates the best overall prediction performance.     

A Model of Equity Based Compensation with Tax

In this paper, we develop a two‐stage continuous time model of employee stock option (ESO) valuation under different tax regimes. We show that tax rules can have significant effects on ESO exercise behavior. In addition, we find that incentive stock options (ISO) are the optimal form of compensation for all levels of employees in the UK. In the US, restricted stock plans are preferred, and tax breaks offered by incentive schemes are only beneficial to employees with high liquid wealth (or small option holdings relative to wealth) or low risk aversion. We also analyze 83b elections for restricted stock plans in the US and find that making an election is a sub‐optimal decision for both the employee and the firm.