Note 11—Income Taxes

The effective income tax rates were 22% and 27% for the three and six months ended March 31, 2014, respectively, and 32% and 30% for the three and six months ended March 31, 2013, respectively. The effective tax rates for the three and six months ended March 31, 2014 differ from the effective tax rates in the same periods in fiscal 2013 primarily due to:


•	a $218 million tax benefit related to a deduction for U.S. domestic production activities, of which, $184 million related to prior fiscal years and $17 million related to the first quarter of fiscal 2014, as a result of the completion of a study during the three months ended March 31, 2014; and


•	the absence of a $76 million tax benefit recognized in the first quarter of fiscal 2013, as a result of new guidance issued by the state of California regarding apportionment rules for years prior to fiscal 2012.

During the three and six months ended March 31, 2014, the Company's gross unrecognized tax benefits increased by $133 million and $180 million, respectively, $132 million and 177 million of which, respectively, would favorably impact our effective income tax rate if recognized. The increase in gross unrecognized tax benefits is primarily due to potential audit exposure related to various tax positions across several jurisdictions. During the three and six months ended March 31, 2014, the Company accrued $2 million and $4 million of interest, respectively, and released $1 million of penalties related to uncertain tax positions.