Earnings per Share

3 Months Ended

Mar. 31, 2017

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 March 31,
	2017			2016
Net income attributable to Westlake Chemical Corporation	$	138,190		$	123,128
Less:
Net income attributable to participating securities	(694		)	(549		)
Net income attributable to common shareholders	$	137,496		$	122,579

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 March 31,
	2017		2016
Weighted average common shares—basic	128,979,357		130,189,964
Plus incremental shares from:
Assumed exercise of options	712,658		410,550
Weighted average common shares—diluted	129,692,015		130,600,514

Earnings per common share attributable to Westlake Chemical Corporation:
Basic	$	1.07	$	0.94
Diluted	$	1.06	$	0.94

Excluded from the computation of diluted earnings per share are options to purchase 437,787 and 555,948 shares of common stock for the three months ended March 31, 2017 and 2016, respectively. These options were outstanding during the periods reported but were excluded because the effect of including them would have been antidilutive.