NOTE 20. INCOME TAXES

The effective tax rate for the three months ended March 31, 2019 included a benefit associated with stock-based compensation, a benefit associated with prior year tax positions and a benefit from a net decrease in the valuation allowance related to state deferred tax assets. These factors resulted in a net $0.8 million tax benefit. After giving consideration to these items, the effective tax rate for the three months ended March 31, 2019 of 23.0% was higher than the 21% U.S. federal statutory rate, primarily due to state and foreign income taxes, foreign income inclusions and a net increase in the valuation allowance related to losses in foreign jurisdictions, partially offset by favorable permanent salt depletion deductions. The effective tax rate for the three months ended March 31, 2018 included a benefit associated with stock-based compensation, a benefit associated with the estimated reduction of the one-time 2017 Tax Act transition tax and a benefit related to a foreign dividend payment. These factors resulted in a net $0.8 million tax benefit. After giving consideration to these items, the effective tax rate for the three months ended March 31, 2018 of 26.9% was higher than the 21% U.S. federal statutory rate, primarily due to state and foreign income taxes, partially offset by favorable permanent salt depletion deductions.

As of March 31, 2019, we had $34.4 million of gross unrecognized tax benefits, which would have a net $33.5 million impact on the effective tax rate, if recognized. As of March 31, 2018, we had $36.8 million of gross unrecognized tax benefits, of which $35.9 million would have impacted the effective tax rate, if recognized. The amount of unrecognized tax benefits was as follows:



	March 31,
	2019		2018
	($ in millions)
Balance at beginning of year	$	33.8	$	36.3
Increases for current year tax positions	0.6		0.5
Balance at end of period	$	34.4	$	36.8

As of March 31, 2019, we believe it is reasonably possible that our total amount of unrecognized tax benefits will decrease by approximately $14.7 million over the next twelve months. The anticipated reduction primarily relates to settlements with taxing authorities and the expiration of federal, state and foreign statutes of limitation.

We operate globally and file income tax returns in numerous jurisdictions. Our tax returns are subject to examination by various federal, state and local tax authorities. None of our U.S. federal income tax returns are currently under examination by the Internal Revenue Service. We believe we have adequately provided for all tax positions; however, amounts asserted by taxing authorities could be greater than our accrued position. For our primary tax jurisdictions, the tax years that remain subject to examination are as follows:



	Tax Years
U.S. federal income tax	2013 - 2018
U.S. state income tax	2006 - 2018
Canadian federal income tax	2012 - 2018
Brazil	2014 - 2018
Germany	2015 - 2018
China	2014 - 2018
The Netherlands	2014 - 2018