Note 5. Income Taxes	6 Months Ended
Jun. 30, 2018
Notes to Financial Statements
Income Taxes	We recognized income tax expense of $224,000 and $214,000 during the three and six-month periods ended June 30, 2018, respectively, compared to $224,000 and $264,000 during the same periods of 2017. At the end of each interim period, we estimate the effective tax rate we expect to be applicable for the full fiscal year and this rate is applied to our results for the year-to-date period, and then adjusted for any discrete period items. For the three-month period ended June 30, 2018, the variance between the Company’s effective tax rate and the U.S. statutory rate of 21% is primarily attributable to additional expense as a result of a tax shortfall associated with stock-based compensation in the amount of $68,000, offset by foreign statutory tax rate differentials and tax credits. For the six-month period ended June 30, 2018, the impact of stock-based compensation resulted in a tax benefit of $4,000. For the three and six-month periods ended June 30, 2017, the variance between the Company’s effective tax rate and the U.S. statutory rate at the time of 34% is primarily attributable to the excess stock-based compensation tax benefit of $45,000 and $122,000, respectively, as well as foreign statutory tax rate differentials and tax credits. The recently signed 2017 Act included a reduction in the federal corporate tax rate to 21% and other key provisions which were effective beginning January 1, 2018. The company has included these effects, as relevant, in the calculation of tax expense for the three and six-month periods ended June 30, 2018.

Note 5. Income Taxes

6 Months Ended

Jun. 30, 2018

We recognized income tax expense of $224,000 and $214,000 during the three and six-month periods ended June 30, 2018, respectively, compared to $224,000 and $264,000 during the same periods of 2017. At the end of each interim period, we estimate the effective tax rate we expect to be applicable for the full fiscal year and this rate is applied to our results for the year-to-date period, and then adjusted for any discrete period items. For the three-month period ended June 30, 2018, the variance between the Company’s effective tax rate and the U.S. statutory rate of 21% is primarily attributable to additional expense as a result of a tax shortfall associated with stock-based compensation in the amount of $68,000, offset by foreign statutory tax rate differentials and tax credits. For the six-month period ended June 30, 2018, the impact of stock-based compensation resulted in a tax benefit of $4,000. For the three and six-month periods ended June 30, 2017, the variance between the Company’s effective tax rate and the U.S. statutory rate at the time of 34% is primarily attributable to the excess stock-based compensation tax benefit of $45,000 and $122,000, respectively, as well as foreign statutory tax rate differentials and tax credits.

The recently signed 2017 Act included a reduction in the federal corporate tax rate to 21% and other key provisions which were effective beginning January 1, 2018. The company has included these effects, as relevant, in the calculation of tax expense for the three and six-month periods ended June 30, 2018.