Generally, accounting standards require companies to provide for income taxes each quarter based on their estimate of the effective tax rate for the full year. The authoritative guidance for accounting for income taxes allows use of the discrete method when it provides a better estimate of income tax expense. Due to the Company’s valuation allowance position, it is the Company’s position that the discrete method provides a more accurate estimate of income tax expense and therefore income tax expense for the current quarter has been presented using the discrete method. As the year progresses, the Company refines its estimate based on the facts and circumstances by each tax jurisdiction. The following table summarizes the income tax (benefit) provision on the loss from continuing operations and the effective tax rate for the three- and nine-month periods ended September 30, 2017 and 2016:

Income tax (benefit) provision for the three- and nine-month periods ended September 30, 2017 and 2016 was primarily due to an allocation of tax expense between continuing and discontinued operations.