
5.	Income Taxes

Our effective income tax rate for the three and six months ended June 30, 2011 was 34.5% and 35.1%, respectively, compared with 44.2% and 41.2% for the comparable prior year periods. We evaluate our effective income tax rate at each interim period and adjust it accordingly as facts and circumstances warrant. The differences between federal income taxes computed at the federal statutory rate and reported income taxes for the three and six months ended June 30, 2011 were primarily due to the favorable impact of federal tax credits offset by the unfavorable impact of state and local income taxes. The differences between federal income taxes computed at the federal statutory rate and reported income taxes for the three and six months ended June 30, 2010 were primarily due to an increase in our state deferred income taxes to reflect the impact of changes in the estimated income tax rate at which temporary differences would be realized and the unfavorable impact of state and local income taxes.

Investment in Refined Coal Facility — In January 2011, we acquired a noncontrolling interest in a limited liability company, which was established to invest in and manage a refined coal facility in North Dakota. The facility’s refinement processes qualify for federal tax credits that are expected to be realized through 2019 in accordance with Section 45 of the Internal Revenue Code. Our initial consideration for this investment consisted of a cash payment of $48 million.

We account for our investment in this entity using the equity method of accounting, recognizing our share of the entity’s results and other reductions in “Equity in net losses of unconsolidated entities,” within our Condensed Consolidated Statement of Operations. During both the three and six months ended June 30, 2011, we recognized $2 million of net losses resulting from our share of the entity’s operating losses. Our tax provision for the three and six months ended June 30, 2011 was reduced by $4 million and $7 million, respectively, primarily as a result of tax credits realized from this investment. See Note 12 for additional information related to this investment.

Investment in Federal Low-income Housing Tax Credits — In April 2010, we acquired a noncontrolling interest in a limited liability company established to invest in and manage low-income housing properties. The entity’s low-income housing investments qualify for federal tax credits that are expected to be realized through 2020 in accordance with Section 42 of the Internal Revenue Code.

We account for our investment in this entity using the equity method of accounting. We recognize our share of the entity’s results and reductions in the value of our investment in “Equity in net losses of unconsolidated entities,” within our Condensed Consolidated Statement of Operations. The value of our investment decreases as the tax credits are generated and utilized. During the three and six months ended June 30, 2011, we recognized $6 million and $12 million of losses for reductions in the value of our investment, $2 million and $4 million of interest expense, and a reduction in our tax provision of $11 million (including $7 million of tax credits) and $18 million (including $11 million of tax credits), respectively. During the three and six months ended June 30, 2010, we recognized $8 million of losses for reductions in the value of our investment, $1 million of interest expense and a reduction in our tax provision of $11 million (including $8 million of tax credits). See Note 12 for additional information related to this investment.

Recent Legislation — The Tax Relief, Unemployment Insurance Reauthorization, and Job Creation Act, signed into law on December 17, 2010, included an extension of the bonus depreciation allowance through the end of 2012 and increased the amount of qualifying capital expenditures that can be depreciated immediately from 50 percent to 100 percent. The 100 percent depreciation deduction applies to qualifying property placed in service from September 8, 2010 through December 31, 2011. The acceleration of deductions on 2011 capital expenditures resulting from the bonus depreciation provision will have no impact on our effective tax rate. However, the ability to accelerate depreciation deductions is expected to decrease our 2011 cash taxes by approximately $190 million. Taking the accelerated tax depreciation will result in increased cash taxes in future periods when the accelerated deductions for these capital expenditures would have otherwise been taken.