
11.	INCOME TAXES

We are required to adjust our effective tax rate each quarter to estimate our annual effective tax rate. We must also record the tax impact of certain discrete, unusual or infrequently occurring items, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, in the interim period in which they occur. In addition, jurisdictions with a projected loss for the year or a year-to-date loss where no tax benefit can be recognized are excluded from the estimated annual effective tax rate. The impact of such an exclusion could result in a higher or lower effective tax rate during a particular quarter, based upon the mix and timing of actual earnings versus annual projections.

Income tax expense was $2.4 million in the three months ended June 30, 2017 as compared to $20.7 million in the three months ended June 30, 2016. Our effective income tax rate was 3.6% in the second quarter of 2017 as compared to 22.6% in the second quarter of 2016. Income tax expense was $9.9 million in the six months ended June 30, 2017 as compared to $36.0 million in the six months ended June 30, 2016. Our effective income tax rate was 6.4% in the first six months of 2017 as compared to 21.4% in the first six months of 2016.

Our effective income tax rate for the three and six months ended June 30, 2017 is lower than our effective income tax rate for the three and six months ended June 30, 2016 primarily as a result of an increase in the proportionate share of income attributable to lower tax rate jurisdictions. In addition, subsequent to the acquisition of MPG, we re-evaluated our valuation allowance position with regard to jurisdictions in which consolidated state tax returns are filed and recorded an income tax benefit for the three months ended June 30, 2017. This was partially offset by a discrete tax adjustment related to certain non-deductible transaction and acquisition-related costs. Our income tax expense and effective tax rate for the three and six months ended June 30, 2017, and June 30, 2016, reflect the impact of favorable foreign tax rates, partially offset by our inability to realize a tax benefit for current foreign losses.

Based on the status of audits outside the U.S., and the protocol of finalizing audits by the relevant tax authorities, it is not possible to estimate the timing or impact of changes, if any, to previously recorded uncertain tax positions. As of June 30, 2017 and December 31, 2016, we have recorded a liability for unrecognized income tax benefits and related interest and penalties of $50.8 million and $30.7 million, respectively. In January 2016, we completed negotiations with the Mexican tax authorities to settle transfer pricing audits. Including these settlements, we made payments of $26.1 million in the first six months of 2016 to the Mexican tax authorities related to transfer pricing matters.

Although it is difficult to estimate with certainty the amount of our tax liabilities for the years that remain subject to audit, we do not expect the settlements will be materially different from what we have recorded in unrecognized tax benefits. We will continue to monitor the progress and conclusions of current and future audits and will adjust our estimated liability as necessary.