anticipate doing so in the foreseeable future. The aforementioned inputs entered into the option valuation model we use to fair value our stock awards are subjective estimates and changes to these estimates will cause the fair value of our stock awards and related stock-based compensation expense we record to vary.

 

We record deferred tax assets for stock-based awards that result in deductions on our income tax returns, based on the amount of stock-based compensation recognized and the statutory tax rate in the jurisdiction in which we will receive a tax deduction. Because the deferred tax assets we record are based upon the stock-based compensation expenses in a particular jurisdiction, the aforementioned inputs that affect the fair value of our stock awards also indirectly affect our income tax expense. In addition, differences between the deferred tax assets recognized for financial reporting purposes and the actual tax deduction reported on our income tax returns are recorded in additional paid-in capital. If the tax deduction is less than the deferred tax asset, such shortfalls reduce our pool of excess tax benefits. If the pool of excess tax benefits is reduced to zero, then subsequent shortfalls would increase our income tax expense. Our pool of excess tax benefits is computed in accordance with the alternative transition method as prescribed under FASB Staff Position FAS 123R-3, Transition Election to Accounting for the Tax Effects of Share-Based Payment Awards .

 

To the extent we change the terms of our employee stock-based compensation programs or refine different assumptions in future periods such as forfeiture rates that differ from our estimates, the stock-based compensation expense that we record in future periods and the tax benefits that we realize may differ significantly from what we have recorded in previous reporting periods.

 

Allowances for Doubtful Accounts

 

We make judgments as to our ability to collect outstanding receivables and provide allowances for the portion of receivables when collection becomes doubtful. Provisions are made based upon a specific review of all significant outstanding invoices. For those invoices not specifically reviewed, provisions are provided at differing rates, based upon the age of the receivable, the collection history associated with the geographic region that the receivable was recorded and current economic trends. If the historical data we use to calculate the allowances for doubtful accounts does not reflect the future ability to collect outstanding receivables, additional provisions for doubtful accounts may be needed and our future results of operations could be materially affected.

 

Results of Operations

 

The comparability of our operating results in fiscal 2008 compared to fiscal 2007 is primarily impacted by our acquisition of Hyperion in our fourth quarter of fiscal 2007, our acquisition of Agile Software, Inc. in our first quarter of fiscal 2008 and our acquisition of BEA in our fourth quarter of fiscal 2008.

 

The comparability of our operating results in fiscal 2007 in comparison to fiscal 2006 is impacted by our acquisition of Siebel in our third quarter