of tradable forward call options to purchase shares of our common stock. Our decision to incorporate implied volatility was based on our assessment that implied volatility of publicly traded options in our common stock is more reflective of market conditions and, therefore, can reasonably be expected to be a better indicator of expected volatility than historical volatility of our common stock. We include the historical volatility in our computation due to low trade volume of our tradable forward call options in certain periods thereby precluding sole reliance on implied volatility. An increase of 10% in our computation of expected volatility would increase the total stock-based compensation expense by approximately $3.1 million.

 

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Suboptimal Exercise Factor: Our computation of the suboptimal exercise factor is based on historical option exercise behavior and the terms and vesting periods of the options granted and is determined for both executives and non-executives. An increase in the suboptimal exercise factor of 10% would increase the total stock-based compensation expense by approximately $2.3 million.



Income Taxes

We record a provision for income taxes for the anticipated tax consequences of our reported results of operations using the asset and liability method. Deferred income taxes are recognized by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases as well as net operating loss and tax credit carryforwards. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. The measurement of deferred tax assets is reduced, if necessary, by a valuation allowance for any tax benefits for which future realization is uncertain.

Although we believe our assumptions, judgments and estimates are reasonable, changes in tax laws or our interpretation of tax laws and the resolution of any tax audits could significantly impact the amounts provided for income taxes in our consolidated financial statements.

In evaluating our ability to recover our deferred tax assets, in full or in part, we consider all available positive and negative evidence, including our past operating results, and our forecast of future earnings, future taxable income and prudent and feasible tax planning strategies. The assumptions utilized in determining future taxable income require significant judgment and are consistent with the plans and estimates we are using to manage the underlying businesses. Actual operating results in future years could differ from our current assumptions, judgments and estimates. However, we believe that it is more likely than not that substantially all deferred tax assets recorded on our Consolidated Balance Sheets will ultimately be realized. In the event we were to determine that we would not be able to realize all or part of our net deferred tax assets in the future, an adjustment to the deferred tax assets would be charged to earnings in the period in which we make such determination.

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