Basic earnings per share is net earnings 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 per share is net earnings 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				YEAR-TO-DATE ENDED
SHARES IN THOUSANDS	SEPTEMBER 2022		SEPTEMBER 2021		SEPTEMBER 2022		SEPTEMBER 2021
Weighted average common shares outstanding – basic		740,058		750,105		743,990		749,657
Dilutive potential common shares:
Stock options		192		293		294		318
Restricted stock units		420		730		417		709
Performance share units		305		315		380		315
Total effect of outstanding dilutive potential common shares		917		1,338		1,091		1,342
Weighted average common shares outstanding – dilutive		740,975		751,443		745,081		750,999

We use the treasury stock method to calculate the dilutive effect of our outstanding stock options, restricted stock units and performance share units.

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				YEAR-TO-DATE ENDED
SHARES IN THOUSANDS	SEPTEMBER 2022		SEPTEMBER 2021		SEPTEMBER 2022		SEPTEMBER 2021
Stock options		620		789		620		789
Performance share units		623		1,067		623		1,067

On September 22, 2021, we announced that our board of directors approved a new share repurchase program (the 2021 Repurchase Program) under which we are authorized to repurchase up to $1 billion of outstanding shares. Concurrently, the board terminated the remaining repurchase authorization under the share repurchase program approved by the board in February 2019 (the 2019 Repurchase Program).

We repurchased 4,234,838 common shares for approximately $145 million (including transaction fees) under the 2021 Repurchase Program during third quarter 2022 and 11,217,300 common shares for approximately $404 million (including transaction fees) under the 2021 Repurchase Program during year-to-date 2022. As of September 30, 2022, we had remaining authorization of $523 million for future share repurchases. During year-to-date 2021, we repurchased 780,228 common shares for approximately $26 million (including transaction fees) under the 2019 Repurchase Program.

All common stock repurchases under the 2019 Repurchase Program and 2021 Repurchase Program were 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 64,135 unsettled shares (approximately $2 million) as of September 30, 2022 and no unsettled shares as of December 31, 2021.