Significant components of the Company’s deferred income tax assets consist of the following:

December 31 (in thousands)	2015			2014
Deferred income tax assets:
Bad debt reserve	$	75		$	93
Accrued expenses		3,865			2,940
State taxes		91			78
Charitable contributions		402			330
Net operating loss		26,186			17,473
Stock options and restricted stock		7,752			6,163
Depreciation		1,661			2,089
Total deferred income tax assets		40,032			29,166
Valuation allowance		(38,390	)		(27,703	)
DEFERRED INCOME TAX ASSETS, NET	$	1,642		$	1,463

The Company has initiated a tax strategy that enables the Company to deduct losses from its foreign subsidiaries against its profitable U.S. operations. Because of this strategy, the decrease in pre-tax earnings of GRE in 2012, and the Company’s current projections, the Company concluded that it no longer met the criteria of more likely than not in order to utilize its deferred federal income tax assets in the foreseeable future. Accordingly, at December 31, 2015 and 2014, only the state portion of GRE deferred tax assets are reflected.

The provision for (benefit from) income taxes consists of the following:

	Year ended December 31,
(in thousands)	2015			2014			2013
Current:
Federal	$	—		$	—		$	1,112
State and local		704			730			1,891
Foreign		—			(12	)		(7	)
		704			718			2,996
Deferred:
Federal		19			68			—
State and local		(198	)		(691	)		(241	)
Foreign		—			—			—
		(179	)		(623	)		(241	)
PROVISION FOR INCOME TAXES	$	525		$	95		$	2,755

The differences between income taxes expected at the U.S. federal statutory income tax rate and income taxes provided are as follows:

	Year ended December 31,
(in thousands)	2015			2014			2013
U.S. federal income tax at statutory rate	$	(2,840	)	$	(9,559	)	$	(904	)
Valuation allowance		2,982			9,564			2,447
Foreign tax rate differential		31			22			48
Other		20			115			66
State and local income tax, net of federal benefit		332			(47	)		1,098
PROVISION FOR INCOME TAXES	$	525		$	95		$	2,755

At December 31, 2015, the Company had U.S. federal and state net operating loss carry-forwards of approximately $26.1 million and $67.2 million, respectively. These carry-forward losses are available to offset future U.S. federal and state taxable income. The federal net operating loss carry-forwards will start to expire in 2032, with the year ended December 31, 2015’s loss expiring in 2036. The state net operating loss carry-forwards will start to expire in 2028, with the year ended December 31, 2015’s loss expiring in 2036.

At December 31, 2015, the Company had foreign net operating loss carry-forwards of approximately $52.0 million, of which $47.4 million will not expire. This carry-forward loss is available to offset future foreign taxable income.

The change in the valuation allowance for deferred income taxes was as follows:

(in thousands)	Balance at beginning of period		Additions charged to costs and expenses		Deductions		Balance at end of period
Year ended December 31, 2015
Reserves for valuation allowances deducted from deferred income taxes, net	$	27,703	$	10,687	$	—	$	38,390
Year ended December 31, 2014
Reserves for valuation allowances deducted from deferred income taxes, net	$	16,653	$	11,050	$	—	$	27,703
Year ended December 31, 2013
Reserves for valuation allowances deducted from deferred income taxes, net	$	11,861	$	4,792	$	—	$	16,653

	Year ended December 31,
(in thousands)	2015			2014			2013
Balance at beginning of period	$	543		$	542		$	223
Additions based on tax positions related to the current period		97			209			—
Additions for tax positions of prior periods		10			9			319
Lapses of statutes of limitations		(14	)		(217	)		—
Balance at end of period	$	636		$	543		$	542

All of the unrecognized income tax benefits at December 31, 2015 and 2014 would have affected the Company’s effective income tax rate if recognized. The Company does not expect the total amount of unrecognized tax benefits to significantly increase or decrease within the next twelve months.

In the years ended December 31, 2015, 2014 and 2013, the Company recorded interest on income taxes of $10,000, $9,000 and $9,000, respectively. As of December 31, 2015 and 2014, there was no accrued interest included in current income taxes payable.

The Company currently remains subject to examinations of its tax returns as follows: U.S. federal tax returns for 2012 to 2015, state and local tax returns generally for 2011 to 2015 and foreign tax returns generally for 2011 to 2015.