NET EARNINGS (LOSS) PER SHARE AND SHARE REPURCHASES

Our basic and diluted earnings (loss) per share were:


•	$(0.39) during first quarter 2019 and


•	$0.35 during first quarter 2018.

Basic earnings (loss) per share is net earnings (loss) divided by the weighted average number of our outstanding common shares, including stock equivalent units where there is no circumstance under which those shares would not be issued. Diluted earnings (loss) per share is net earnings (loss) divided by the sum of the weighted average number of our outstanding common shares and the effect of our outstanding dilutive potential common shares.



	QUARTER ENDED
SHARES IN THOUSANDS	MARCH 2019	MARCH 2018
Weighted average common shares outstanding – basic	746,603	756,815
Dilutive potential common shares:
Stock options	—	1,682
Restricted stock units	—	569
Performance share units	—	396
Total effect of outstanding dilutive potential common shares	—	2,647
Weighted average common shares outstanding – dilutive	746,603	759,462

We use the treasury stock method to calculate the dilutive effect of our outstanding stock options, restricted stock units and performance share units. Share-based payment awards that are contingently issuable upon the achievement of specified performance or market conditions are included in our diluted earnings per share calculation in the period in which the conditions are satisfied.

Potential Shares Not Included in the Computation of Diluted Earnings per Share

The following shares were not included in the computation of diluted earnings per share because they were either antidilutive or the required performance or market conditions were not met. Some or all of these shares may be dilutive potential common shares in future periods.



	QUARTER ENDED
SHARES IN THOUSANDS	MARCH 2019	MARCH 2018
Stock options	2,862	1,301
Restricted stock units	383	—
Performance share units	1,356	744

Share Repurchase Program

On February 7, 2019, our board of directors approved and announced a new share repurchase program (the 2019 Repurchase Program) under which we are authorized to repurchase up to $500 million of outstanding shares. On the same day, the board terminated the remaining repurchase authorization under the share repurchase program approved by the board in November 2015.

During first quarter 2019, we repurchased over 2.3 million common shares for approximately $60 million under the 2019 Repurchase Program. As of March 31, 2019, we had remaining authorization of $440 million for future share repurchases. We did not repurchase shares during first quarter 2018.

All common share purchases under the share repurchase program are expected to be made in open-market transactions. We record share repurchases upon trade date as opposed to the settlement date when cash is disbursed. We record a liability for repurchases that have not yet been settled as of period end. There were no unsettled repurchases as of March 31, 2019 or December 31, 2018.