Venezuelan currency by the Venezuelan government. In addition, our interest income increased in fiscal 2011 due to larger average cash, cash equivalents and marketable securities balances and other income, net increased in fiscal 2011 as a result of gains recognized on the sale of certain equity investments.

Provision for Income Taxes:     Our effective tax rate in all periods is the result of the mix of income earned in various tax jurisdictions that apply a broad range of income tax rates. The provision for income taxes differs from the tax computed at the U.S. federal statutory income tax rate due primarily to earnings considered as indefinitely reinvested in foreign operations, state taxes, the U.S. research and development tax credit and the U.S. domestic production activity deduction. Future effective tax rates could be adversely affected if earnings are lower than anticipated in countries where we have lower statutory tax rates, by unfavorable changes in tax laws and regulations or by adverse rulings in tax related litigation.

 

Fiscal 2012 Compared to Fiscal 2011:     Provision for income taxes increased during fiscal 2012 due substantially to higher income before provision for income taxes, partially offset by the favorable effects of an increase in the number of foreign subsidiaries in countries with lower statutory rates than the United States, the earnings of which we consider to be indefinitely reinvested outside the United States. If these subsidiaries generate sufficient earnings in the future, our provision for income taxes may continue to be favorably affected to a meaningful extent, although any such favorable effects could be significantly reduced under a variety of circumstances.

Fiscal 2011 Compared to Fiscal 2010:     Provision for income taxes increased during fiscal 2011 due substantially to higher income before provision for income taxes and a reduction in the impact of favorable judicial decisions and settlements with worldwide taxing authorities.

Liquidity and Capital Resources

 

Working capital:     The decrease in working capital as of May 31, 2012 in comparison to May 31, 2011 was primarily due to an increase in our stock repurchases during fiscal 2012 in comparison to fiscal 2011 (we used $5.9 billion of cash for stock repurchases during fiscal 2012 in comparison to $1.2 billion used for stock repurchases during fiscal 2011), the reclassification of $1.25 billion of our senior notes due April 2013 as a current liability, cash used for acquisitions and cash used to pay dividends to our stockholders. These decreases to working capital were almost entirely offset by the favorable impact to our net current assets resulting from our net income during fiscal 2012. Our working capital may be impacted by some of the aforementioned factors in future periods, certain amounts and timing of which are variable.

The increase in working capital as of May 31, 2011 in comparison to May 31, 2010 was primarily due to the favorable impact to our net current assets resulting from our net income during fiscal 2011 and our issuance of $3.25 billion of long-term senior notes in July 2010. These increases were partially offset