Earnings per Share

6 Months Ended

Jun. 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 June 30,						Six Months Ended June 30,
	2015			2014			2015			2014
Net income attributable to Westlake Chemical Corporation	$	205,095		$	169,443		$	351,437		$	327,475
Less:
Net income attributable to participating securities	(253		)	(360		)	(457		)	(746		)
Net income attributable to common shareholders	$	204,842		$	169,083		$	350,980		$	326,729

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 June 30,				Six Months Ended June 30,
	2015		2014		2015		2014
Weighted average common shares—basic	132,538,123		133,223,705		132,625,857		133,148,398
Plus incremental shares from:
Assumed exercise of options	506,852		544,185		498,840		542,438
Weighted average common shares—diluted	133,044,975		133,767,890		133,124,697		133,690,836

Earnings per common share attributable to Westlake Chemical Corporation:
Basic	$	1.55	$	1.27	$	2.65	$	2.45
Diluted	$	1.54	$	1.26	$	2.64	$	2.44

Excluded from the computation of diluted earnings per share are options to purchase 330,315 and 134,938 shares of common stock for the three months ended June 30, 2015 and 2014, respectively, and 285,933 and 102,480 shares of common stock for the six months ended June 30, 2015 and 2014, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive.