Income Taxes

The following table provides details of income taxes (in thousands, except percentages):



	Three months ended
	March 31,
	2014			2013
Loss before provision for income taxes		($3,966	)		($4,128	)
Provision for income taxes	251			306
Effective tax rate	(6		)%	(7		)%

The effective tax rate for the three months ended March 31, 2014 fluctuates based on the amount of pre-tax income or loss generated in the various jurisdictions where we conduct operations and pay income tax. In addition, various jurisdictions that generate losses do not benefit from the losses generated due to a valuation allowance placed on those benefits

As of December 31, 2013, we had net operating losses ("NOLs") of $172.3 million, $93.1 million, and $95.8 million for federal, state, and foreign income tax purposes, respectively. Additionally, the Company had capital loss carryforwards of $110.5 million and $24.0 million for federal and state tax purposes, respectively. The capital loss carry forwards, which were generated by the sale of Source Photonics, expire in 2015. Under the Internal Revenue Code, if a corporation undergoes an "ownership change," the corporation's ability to use its pre-change NOLs, capital loss carry forwards and other pre-change tax attributes to offset its post-change income may be limited. An ownership change is generally defined as a greater than 50% change in its equity ownership by value over a three-year period. We may experience an ownership change in the future as a result of subsequent shifts in our stock ownership. If we were to trigger an ownership change in the future, our ability to use any NOLs and capital loss carry forwards existing at that time could be limited. As of March 31, 2014, the US federal and state NOLs had a full valuation allowance.