Unvested restricted stock awards have the right to receive nonforfeitable dividends on the same basis as common shares; therefore, unvested restricted stock is considered a participating security for the purpose of calculating EPS. Historically, the Company has shown EPS for its common stock and unvested restricted stock on a combined basis since both instruments participate on the same basis and the resulting EPS is typically the same. Starting under the two-class method, the Company reports separately the net earnings allocated away from holders of Class A and Class B common stock to holders of unvested restricted stock awards.
For accounting purposes, Class B’s participation rights are, in substance, discretionary based on the power of the Company’s Board of Directors to add or modify expense allocation policies, redefine CORE assets, and redetermine CORE’s per-ton usage fees at any time, in its sole discretion, without shareholder approval. Therefore, no amount of the Company’s net earnings shall be allocated to Class B for the purpose of calculating EPS other than actual dividends declared during the period for the tracking stock. Refer to Note 6 for information regarding dividends declared on Class B common stock.
Diluted EPS was calculated using the treasury stock method for stock options and restricted stock units. For performance stock units, the awards were first evaluated under the contingently issuable shares guidance, which requires a determination as to whether shares would be issuable if the end of the reporting period were the end of the contingency period. For shares determined to be issuable under performance stock unit awards, the treasury stock method was then applied to determine the dilutive impact of the awards, if any. Unvested restricted stock awards are considered potential common shares as well as participating securities, as discussed previously, and were included in diluted EPS using the more dilutive of the treasury stock method or the two-class method. Since these awards share in dividends on a 1:1 basis with common shares, applying the treasury stock method was antidilutive compared to the basic EPS calculation that allocates earnings to participating securities under the two-class method discussed previously.
Diluted EPS for the period from January 1, 2023 through June 20, 2023, the period for which a single class of common stock existed, excluded all outstanding restricted stock units, or 684,151 units in total, because the effect would have been antidilutive under the treasury stock method. In addition, diluted EPS for the same period excluded outstanding performance stock units originally granted in 2022, or 248,706 units at target, based on the guidance for contingently issuable shares, which requires exclusion when shares would not be issuable if the end of the reporting period were the end of the contingency period.
For the third quarter of 2023 and the period from June 21,2023 through September 30, 2023, diluted EPS for Class A common stock excluded 165,803 RSUs because the effect would have been antidilutive under the treasury stock method. Class A diluted EPS for these periods also excluded outstanding performance stock units originally granted in 2022, or approximately 153,452 units if September 30, 2023 were the end of the contingency period, because the effect would have been antidilutive under the treasury stock method. The same performance stock unit awards, or 248,706 units at target, were excluded in the previous reporting period based on the guidance for contingently issuable shares. In addition, the Company’s ability to convert Class B common shares into Class A common shares, as discussed previously in Note 6, is a contingency that will not be reflected in the diluted EPS for Class A under the if-converted method until such time that the required Board resolutions occur, if ever.
For the third quarter of 2023 and the period from June 21, 2023 through September 30, 2023, diluted EPS for Class B common stock excluded certain performance stock units, or approximately 30,688 units if September 30, 2023 were the end of the contingency period, because the effect would have been antidilutive under the treasury stock method. The same awards, or 49,737 units at target, were excluded in the previous reporting period based on the guidance for contingently issuable shares.
Diluted EPS for the single class of common stock in the third quarter of 2022 excluded 248,706 RSUs because the effect would have been antidilutive under the treasury stock method and 248,706 performance stock units, at target, based on the guidance for contingently issuable shares. The performance stock units were excluded from diluted EPS for the single class of common stock for the nine months ended September 30, 2022 as well.