v3.20.1

Basic and diluted earnings per share | 3 Months Ended
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Mar. 31, 2020
Basic and diluted earnings per share |
Basic and diluted earnings per share | 10. Basic and diluted earnings per share Basic earnings per share is calculated by dividing net income attributable to Atlantic Power Corporation by weighted average common shares outstanding during their respective periods. Shares issued and shares repurchased during the year are weighted for the portion of the year that they were outstanding. Diluted earnings per share is computed in a manner consistent with that of basic earnings per share while giving effect to all potentially dilutive common shares that were outstanding during the period. The dilutive effect of our Series E Debentures is calculated using the “if-converted method.” Under the if-converted method, the Series E Debentures are assumed to be converted at the beginning of the period, and the resulting common shares are included in the denominator of the diluted earnings per share calculation for the entire period being presented. Interest expense, net of any income tax effects, would be added back to the numerator for purposes of the if-converted calculation. The outstanding equity compensation for non-vested LTIP and Transition Equity Participation Agreement notional shares are not considered outstanding for purposes of computing basic earnings per share. However, these instruments are included in the denominator, when dilutive, for purposes of computing diluted earnings per share under the treasury stock method. The following table sets forth the calculation of basic and diluted earnings per share for the three months ended March 31, 2020 and 2019:
Basic |  | 2020 |  | 2019
Numerator: |  |  |  |  |  |
Income attributable to Atlantic Power Corporation |  | $ | 29.5 |  | $ | 8.9
Denominator: |  |  |  |  |  |
Weighted average basic shares outstanding |  |  | 107.2 |  |  | 108.9
Basic earnings per share attributable to Atlantic Power Corporation |  | $ | 0.28 |  | $ | 0.08
Diluted |  |  |  |  |  |
Numerator: |  |  |  |  |  |
Net income attributable to Atlantic Power Corporation |  | $ | 29.5 |  | $ | 8.9
Add: convertible debenture interest expense |  |  | 0.9 |  |  | 1.3
|  |  | 30.4 |  |  | 10.2
Denominator: |  |  |  |  |  |
Weighted average basic shares outstanding |  |  | 107.2 |  |  | 108.9
Convertible debentures |  |  | 27.4 |  |  | 29.1
Share-based compensation |  |  | 0.2 |  |  | 0.6
|  |  | 134.8 |  |  | 138.6
Diluted earnings per share attributable to Atlantic Power Corporation |  | $ | 0.23 |  | $ | 0.07

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- Definition The entire disclosure for earnings per share. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -URI http://asc.fasb.org/topic&trid=2144383 + Details
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