S. Earnings Per Share

Basic earnings per share (EPS) amounts are computed by dividing earnings, after the deduction of preferred stock dividends declared and dividends and undistributed earnings allocated to participating securities, by the average number of common shares outstanding. Diluted EPS amounts assume the issuance of common stock for all potentially dilutive share equivalents outstanding not classified as participating securities.

The information used to compute basic and diluted EPS attributable to Alcoa common shareholders was as follows (shares in millions):


	2014		2013			2012
Net income (loss) attributable to Alcoa common shareholders	$	268	$	(2,285	)	$	191
Less: preferred stock dividends declared		21		2			2
Net income (loss) available to common equity		247		(2,287	)		189
Less: dividends and undistributed earnings allocated to participating securities		-		-			-
Net income (loss) available to Alcoa common shareholders—basic		247		(2,287	)		189
Add: interest expense related to convertible notes		-		-			-
Add: dividends related to mandatory convertible preferred stock		-		-			-
Net income (loss) available to Alcoa common shareholders—diluted	$	247	$	(2,287	)	$	189
Average shares outstanding—basic		1,162		1,070			1,067
Effect of dilutive securities:
Stock options		7		-			3
Stock and performance awards		11		-			6
Convertible notes		-		-			-
Mandatory convertible preferred stock		-		-			-
Average shares outstanding—diluted		1,180		1,070			1,076

Participating securities are defined as unvested share-based payment awards that contain nonforfeitable rights to dividends or dividend equivalents (whether paid or unpaid) and are included in the computation of EPS pursuant to the two-class method. Prior to January 1, 2010, under Alcoa’s stock-based compensation programs, certain employees were granted stock and performance awards, which entitle those employees to receive nonforfeitable dividends during the vesting period on a basis equivalent to the dividends paid to holders of Alcoa’s common stock. As such, these unvested stock and performance awards met the definition of a participating security. Under the two-class method, all earnings, whether distributed or undistributed, are allocated to each class of common stock and participating securities based on their respective rights to receive dividends. At the end of all three years presented, there were no outstanding participating securities, as all such securities have vested and were converted into shares of common stock.

Effective January 1, 2010, new grants of stock and performance awards do not contain a nonforfeitable right to dividends during the vesting period. As a result, an employee will forfeit the right to dividends accrued on unvested awards if that person does not fulfill their service requirement during the vesting period. As such, these awards are not treated as participating securities in the EPS calculation as the employees do not have equivalent dividend rights as common shareholders. These awards are included in the EPS calculation utilizing the treasury stock method similar to stock options. At December 31, 2014, 2013, and 2012, there were 19 million, 16 million, and 12 million such awards outstanding, respectively.

In 2014, 16 million and 22 million share equivalents related to convertible notes and mandatory convertible preferred stock, respectively, were not included in the computation of diluted EPS because their effect was anti-dilutive.

In 2013, basic average shares outstanding and diluted average shares outstanding were the same because the effect of potential shares of common stock was anti-dilutive since Alcoa generated a net loss. As a result, 89 million share equivalents related to convertible notes, 16 million stock awards, and 12 million stock options were not included in the computation of diluted EPS. Had Alcoa generated sufficient income from continuing operations in 2013, 89 million, 9 million, and 2 million potential shares of common stock related to the convertible notes, stock awards, and stock options, respectively, would have been included in diluted average shares outstanding.

In 2012, 89 million share equivalents related to convertible notes were not included in the computation of diluted EPS because their effect was anti-dilutive.

Options to purchase 3 million, 12 million, and 27 million shares of common stock at a weighted average exercise price of $16.24, $15.81, and $15.41 per share were outstanding as of December 31, 2014, 2013, and 2012, respectively, but were not included in the computation of diluted EPS because they were anti-dilutive, as the exercise prices of the options were greater than the average market price of Alcoa’s common stock.