INCOME TAXES

A reconciliation of income tax expense (benefit), computed by applying the federal statutory rate to pre-tax income (loss) to our effective income tax expense (benefit) is as follows:



	2015			2014		2013
	(In thousands)
Income tax expense (benefit) computed by applying the statutory rate	$	(582,508	)	$	78,029	$	105,514
State income tax, net of federal benefit	(45,768		)	6,131		8,290
Statutory depletion and other	1,328			2,503		2,919
Income tax expense (benefit)	$	(626,948	)	$	86,663	$	116,723

For the periods indicated, the total provision for income taxes consisted of the following:



	2015			2014		2013
	(In thousands)
Current taxes:
Federal	$	(20,612	)	$	8,594	$	15,845
State	(4		)	784		146
	(20,616		)	9,378		15,991
Deferred taxes:
Federal	(535,691		)	68,360		87,839
State	(70,641		)	8,925		12,893
	(606,332		)	77,285		100,732
Total provision	$	(626,948	)	$	86,663	$	116,723

Deferred tax assets and liabilities are comprised of the following at December 31:



	2015			2014
	(In thousands)
Deferred tax assets:
Allowance for losses and nondeductible accruals	$	56,479		$	55,231
Net operating loss carryforward	140,863			54,901
Alternative minimum tax and research and development tax credit carryforward	5,409			25,991
	202,751			136,123
Deferred tax liability:
Depreciation, depletion, amortization, and impairment	(464,295		)	(1,000,811		)
Net deferred tax liability	(261,544		)	(864,688		)
Current deferred tax asset	14,206			11,527
Non-current—deferred tax liability	$	(275,750	)	$	(876,215	)

Realization of the deferred tax assets are dependent on generating sufficient future taxable income. Although realization is not assured, management believes it is more likely than not that the deferred tax asset will be realized. The amount of the deferred tax asset considered realizable, however, could be reduced in the near-term if estimates of future taxable income are reduced. At December 31, 2015, we have federal net operating loss carryforwards of approximately $351.4 million which expire from 2021 to 2035.

We file income tax returns in the U.S. federal jurisdiction and various states. We are no longer subject to U.S. federal or state income tax examinations by tax authorities for years before 2012. During 2014, we recognized a tax benefit relating to a research and development tax credit carryforward in conjunction with our BOSS drilling rig activities. Due to the nature and subjectivity surrounding the research and development credit and historical challenges by the IRS against companies who claim the credit, it is our belief that the full amount of the credit may not be eventually allowed by the IRS once we are no longer in an AMT tax paying position. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:



	2015		2014		2013
	(In thousands)
Balance at January 1:	$	410	$	—	$	—
Additions based on tax positions related to current year	—		410		—
Additions for tax positions of prior years	—		—		—
Reductions for tax positions of prior years	—		—		—
Settlements	—		—		—
Balance at December 31:	$	410	$	410	$	—

At December 31, 2015 and 2014, there was $0.4 million of unrecognized tax benefits that if recognized would affect the annual effective tax rate. We did not have any unrecognized tax benefits in 2013.