16.	Income Taxes

The following table presents the (benefit) provision for income taxes and the effective tax rates:

(in thousands)	Three months ended March 31,
	2019			2018
(Benefit) provision for income taxes	$	(1,848	)		$	259
Effective tax rate		30.4	%			(20.9	)%

The Company's income tax (benefit) provision for interim periods is determined using an estimate of its annual effective tax rate, adjusted for discrete items arising in that quarter. Tax expense in 2019 is comprised mainly of the tax impact of the loss for impairment, federal income tax expense, foreign income tax expense, and state tax expense. Tax expense in 2018 is comprised mainly of federal income tax expense, foreign income tax expense, and state tax expense.

Our effective tax rate was 30.4% for the three months ended March 31, 2019. For the three months ended March 31, 2019, the difference between our effective tax rate of 30.4% and the U.S. statutory federal income tax rate of 21% was primarily due to permanent differences, accruals related to uncertain tax positions for certain U.S. and foreign tax contingencies, a change in valuation allowance in our China subsidiary, discrete item adjustments for the U.S. and foreign taxes, including the tax impact of the loss for impairment, and the excess book deduction related to stock options and restricted stock units that were exercised or vested during the quarter. For the three months ended March 31, 2018, the difference between the effective tax rate of (20.9)% and the U.S. statutory federal income tax rate of 21% was primarily due to our China subsidiary which had taxable income for the three months ended March 31, 2018 and the accruals related to uncertain tax positions for certain foreign tax contingencies.

Because of its net operating loss carryforwards, the Company is subject to U.S. federal and state income tax examinations from the year 2000 and forward. The Company is subject to foreign tax examinations by tax authorities for years 2011 forward for Sweden, 2015 forward for China, 2015 forward for India, and 2016 forward for the UK.

An uncertain tax position taken or expected to be taken in a tax return is recognized in the consolidated financial statements when it is more likely than not (i.e., a likelihood of more than 50%) that the position would be sustained upon examination by tax authorities that have full knowledge of all relevant information. A recognized tax position is then measured at the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. Interest and penalties related to income taxes are accounted for as income tax expense.

The Company recognizes deferred tax assets to the extent that it is believed that these assets are more likely than not to be realized. The Company has evaluated all positive and negative evidence and determined that it will continue to assess a full valuation allowance on its India, Swedish and U.K. net deferred assets as of March 31, 2019. The Company has determined that it will continue to assess a valuation allowance on its China deferred tax asset related to transfer pricing. The Company has determined that it is more likely than not that it will realize the benefits of its deferred taxes in the U.S.