For the years ended December 31, 2017, 2018, and 2019, income tax expense consisted of the following:


	Year Ended December 31,
(in thousands)	2017		2018		2019
Current income tax expense (benefit)	$	26,261		33,615		(539)
Deferred income tax expense (benefit)		—		(1,304)		(101,927)
Total income tax expense (benefit)	$	26,261		32,311		(102,466)

Income tax expense differs from the amount that would be computed by applying the U.S. statutory federal income tax rate of 35% for the year ended December 31, 2017, and 21% for the years ended December 31, 2018 and 2019, to income before taxes as a result of the following:


	Year Ended December 31,
(in thousands)	2017		2018		2019
Federal income tax expense (benefit)	$	10,005		20,773		(96,092)
State income tax expense (benefit), net of federal benefit		952		4,133		(17,089)
Non-deductible equity-based compensation		13,296		8,087		13,694
Non-deductible IPO expenses		1,948		1		—
Charitable contributions		—		—		(2,473)
Other		60		(683)		(506)
Total income tax expense (benefit)	$	26,261		32,311		(102,466)

Deferred income taxes reflect the impact of temporary differences between assets and liabilities for financial reporting purposes and such amounts as measured by tax laws. The tax effect of the temporary differences giving rise to net deferred tax assets as follows:


	Year Ended December 31,
(in thousands)	2018		2019
Deferred tax assets:
Net operating loss carryforwards	$	—		68,614
Investment in Antero Midstream Partners		—		28,381
Transaction costs		1,304		2,465
Equity-based compensation		—		1,298
Charitable contributions		—		2,473
Total deferred tax assets		1,304		103,231
Valuation allowance		—		—
Net deferred tax assets		1,304		103,231
Deferred tax liabilities:
Net deferred tax liabilities		—		—
Net deferred tax assets (liabilities)	$	1,304		103,231

As of December 31, 2019, the Company has a deferred tax asset in its Investment in Antero Midstream Partners of $28 million. At the time of the Transactions on March 12, 2019, the investment in Antero Midstream Partners was recorded at fair value for both GAAP and income tax purposes. The GAAP versus tax treatment of activity occurring after the transaction, such as the treatment of impairments and differing recovery rates of the underlying assets, gave rise to the deferred tax asset. Due to Antero Midstream Partners’ strong history of pre-tax earnings, the Company believes the benefits of this deferred tax asset will be realized. Additionally, as of December 31, 2019, the Company has U.S. federal and state NOL carryforwards before the effect of income taxes of $277 million and $202 million, respectively, which have no expiration date.

In assessing the realizability of all of the deferred tax assets, management considers whether some portion or all of the deferred tax assets will be realized based on a more-likely-than-not standard of judgment. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which the Company’s temporary differences become deductible. Management considers projected future taxable income and tax planning strategies in making this assessment. Based upon the projections of future taxable income over the periods in which the deferred tax assets are deductible, management believes that the Company will realize the benefits of these deductible differences and thus has not recorded a valuation allowance.