Earnings per Share

9 Months Ended

Sep. 30, 2015

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,
	2015			2014			2015			2014
Net income attributable to Westlake Chemical Corporation	$	183,604		$	167,757		$	535,041		$	495,232
Less:
Net income attributable to participating securities	(195		)	(353		)	(653		)	(1,099		)
Net income attributable to common shareholders	$	183,409		$	167,404		$	534,388		$	494,133

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,
	2015		2014		2015		2014
Weighted average common shares—basic	131,664,296		133,299,458		132,301,814		133,199,304
Plus incremental shares from:
Assumed exercise of options	456,939		546,601		484,720		543,841
Weighted average common shares—diluted	132,121,235		133,846,059		132,786,534		133,743,145

Earnings per common share attributable to Westlake Chemical Corporation:
Basic	$	1.39	$	1.26	$	4.04	$	3.71
Diluted	$	1.39	$	1.25	$	4.02	$	3.69

Excluded from the computation of diluted earnings per share are options to purchase 315,285 and 295,825 shares of common stock for the three and nine months ended September 30, 2015, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive. There were no options excluded from the computation of diluted earnings per share for the three and nine months ended September 30, 2014.