and the carrying value. We estimate the fair value of the reporting units using discounted cash flows. Forecasts of future cash flow are based on our best estimate of future net sales and operating expenses, based primarily on expected category expansion, pricing, market segment penetration and general economic conditions. Certain estimates of discounted cash flows involve businesses and geographies with limited financial history and developing revenue models. Changes in these forecasts could significantly change the amount of impairment recorded, if any. 

During the year, management monitors the actual performance of the business relative to the fair value assumptions used during our annual goodwill impairment test. For the periods presented, we did not identify any triggering events which would require an update to our annual impairment test. A 10% decrease in the fair value of any of our reporting units as of December 31, 2009 would have had no impact on the carrying value of our goodwill. 

Financial and credit market volatility directly impacts our fair value measurement through our weighted average cost of capital that we use to determine our discount rate and through our stock price that we use to determine our market capitalization. During times of volatility, significant judgment must be applied to determine whether credit or stock price changes are a short term swing or a longer-term trend. As a measure of sensitivity, a prolonged 20% decrease from our December 31, 2009 closing stock price would not be an indicator of possible impairment. 

Stock-Based Compensation 

We measure compensation cost for stock awards at fair value and recognize the expense as compensation expense over the service period for awards expected to vest. The fair value of restricted stock units is determined based on the number of shares granted and the quoted price of our common stock. The estimation of stock awards that will ultimately vest requires judgment for the amount that will be forfeited, and to the extent actual results or updated estimates differ from our current estimates, such amounts will be recorded as a cumulative adjustment in the period estimates are revised. We consider many factors when estimating expected forfeitures, including types of awards, employee class, current economic environment, and historical experience. We update our estimated forfeiture rate quarterly. A 1% change to our estimated forfeiture rate would have an approximately $13 million impact on our 2009 consolidated operating income. Our estimated forfeiture rates at December 31, 2009 and 2008 were 33.1% and 37.1%. 

We utilize the accelerated method, rather than the straight-line method, for recognizing compensation expense. Under this method, over 50% of the compensation cost is expensed in the first year of a four-year vesting term. The accelerated method also adds a higher level of sensitivity and complexity in estimating forfeitures. If forfeited early in the life of an award, the forfeited amount is much greater under an accelerated method than under a straight-line method. 

Income Taxes 

We are subject to income taxes in both the U.S. and numerous foreign