7. INCOME TAXES

The components of income tax expense (benefit) are as follows:



	Year Ended December 31,
thousands	2014			2013			2012
Current income tax expense (benefit)
Federal income tax expense (benefit)	$	(625	)	$	(30,222	)	$	48,223
State income tax expense (benefit)	69			636			2,924
Total current income tax expense (benefit)	(556		)	(29,586		)	51,147
Deferred income tax expense (benefit)
Federal income tax expense (benefit)	171			32,930			(9,144		)
State income tax expense (benefit)	2,412			(1,039		)	6,881
Total deferred income tax expense (benefit)	2,583			31,891			(2,263		)
Total income tax expense	$	2,027		$	2,305		$	48,884

Total income taxes differed from the amounts computed by applying the statutory income tax rate to income before income taxes. The sources of these differences are as follows:



	Year Ended December 31,
thousands except percentages	2014			2013			2012
Income before income taxes	$	389,406		$	284,183		$	169,441
Statutory tax rate	—		%	—		%	—		%
Tax computed at statutory rate	$	—		$	—		$	—
Adjustments resulting from:
Federal taxes on income attributable to Anadarko’s investment in WES	(454		)	3,043			41,557
State taxes on income attributable to Anadarko’s investment in WES (net of federal benefit)	—			621			6,069
Texas margin tax expense (benefit)	2,481			(1,359		)	1,258
Income tax expense	$	2,027		$	2,305		$	48,884
Effective tax rate	1		%	1		%	29		%

The tax effects of temporary differences that give rise to significant portions of deferred tax assets (liabilities) are as follows:



	December 31,
thousands	2014			2013
Credit carryforwards	$	14		$	14
Net current deferred income tax assets	14			14
Depreciable property	(3,240		)	(38,528		)
Credit carryforwards	512			527
Other intangible assets	(1,450		)	—
Other	7			3
Net long-term deferred income tax liabilities	(4,171		)	(37,998		)
Total net deferred income tax liabilities	$	(4,157	)	$	(37,984	)

Credit carryforwards, which are available for use on future income tax returns, consist of $0.5 million of state income tax credits that expire in 2026.