Note 12. Earnings Per Share

Basic earnings per share is computed under the two-class method by dividing income available to Class A common stockholders by the weighted average number of Class A common shares outstanding during the period. Unvested restricted share-based awards are excluded from the number of Class A common shares outstanding for the basic earnings per share calculation because the shares have not yet been earned by employees. Income available to Class A common stockholders is computed by reducing net income attributable to APAM by earnings (distributed and undistributed) allocated to participating securities, according to their respective rights to participate in those earnings. Unvested share-based awards are participating securities because the awards include non-forfeitable dividend rights during the vesting period. Class B and Class C common shares do not share in profits of APAM and therefore are not reflected in the calculations.

The computation of basic and diluted earnings per share under the two-class method for the three and nine months ended September 30, 2017 and 2016 were as follows:



	For the Three Months Ended September 30,				For the Nine Months Ended September 30,
Basic and Diluted Earnings Per Share	2017		2016		2017		2016
Numerator:
Net income attributable to APAM	$	30,665	$	19,086	$	77,092	$	53,731
Less: Allocation to participating securities	2,654		3,407		12,086		10,294
Net income available to common stockholders	$	28,011	$	15,679	$	65,006	$	43,437
Denominator:
Weighted average shares outstanding	45,890,291		38,646,194		44,068,172		37,883,039
Earnings per share	$	0.61	$	0.41	$	1.48	$	1.15

Allocation to participating securities in the table above generally represents dividends paid to holders of unvested restricted share-based awards and reduces net income available to common stockholders.

There were no dilutive securities outstanding during the three and nine months ended September 30, 2017 and 2016. The Holdings limited partnership units are anti-dilutive primarily due to the impact of public company expenses and unrecognized share-based compensation expense. Unvested restricted share-based awards are considered participating securities and are therefore anti-dilutive. The following table summarizes the weighted-average shares outstanding that are excluded from the calculation of diluted earnings per share because their effect would have been anti-dilutive:



	For the Three Months Ended September 30,		For the Nine Months Ended September 30,
Anti-Dilutive Weighted Average Shares Outstanding	2017	2016	2017	2016
Holdings limited partnership units	25,715,238	32,406,438	27,318,732	32,955,746
Unvested restricted share-based awards	4,189,441	3,590,680	4,200,142	3,622,230
Total	29,904,679	35,997,118	31,518,874	36,577,976