Earnings per Share

9 Months Ended

Sep. 30, 2016

The Company has unvested shares of restricted stock and restricted stock units outstanding that are considered participating securities and, therefore, computes basic and diluted earnings per share under the two-class method. Basic earnings per share for the periods are based upon the weighted average number of shares of common stock outstanding during the periods. Diluted earnings per share include the effect of certain stock options.



	Three Months Ended September 30,						Nine Months Ended September 30,
	2016			2015			2016			2015
Net income attributable to Westlake Chemical Corporation	$	65,662		$	183,604		$	299,914		$	535,041
Less:
Net income attributable to participating securities	(294		)	(195		)	(1,347		)	(653		)
Net income attributable to common shareholders	$	65,368		$	183,409		$	298,567		$	534,388

The following table reconciles the denominator for the basic and diluted earnings per share computations shown in the consolidated statements of operations:



	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Weighted average common shares—basic	128,793,661		131,664,296		129,519,577		132,301,814
Plus incremental shares from:
Assumed exercise of options	586,295		456,939		584,320		484,720
Weighted average common shares—diluted	129,379,956		132,121,235		130,103,897		132,786,534

Earnings per common share attributable to Westlake Chemical Corporation:
Basic	$	0.51	$	1.39	$	2.31	$	4.04
Diluted	$	0.51	$	1.39	$	2.29	$	4.02

Excluded from the computation of diluted earnings per share are options to purchase 620,010 and 315,285 shares of common stock for the three months ended September 30, 2016 and 2015, respectively, and 577,254 and 295,825 shares of common stock for the nine months ended September 30, 2016 and 2015, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive.