3. Common Stock and Earnings Per Share

Net income of $3,705 and $4,002 for the three months ended March 31, 2021 and 2020, respectively, is used to calculate both basic and diluted earnings per share. Basic earnings per share is based on the weighted average number of common shares outstanding. Diluted earnings per share is based on the weighted average number of common shares outstanding plus potentially dilutive shares. The dilutive effect of employee stock-based compensation is included in the computation of diluted earnings per share and is calculated using the treasury stock method and expected proceeds upon exercise or issuance of the stock-based compensation.

The following table summarizes the shares used in computing basic and diluted earnings per share:

	Three Months Ended March 31
	2021		2020

Weighted average common shares, basic		13,055,871		13,009,596
Effect of dilutive securities:
Employee stock-based compensation		2,690		2,263
Weighted average common shares, diluted		13,058,561		13,011,859

On March 11, 2013, the Board of Directors, or the Board, authorized a share repurchase program granting the Company authority to repurchase up to 1,200,000 shares of the Company's common stock from time to time. The stock repurchase program has no specific end date and the Company may repurchase shares in the open market or through privately negotiated transactions. The Company may suspend or discontinue the repurchase program at any time. No shares were repurchased during the three months ended March 31, 2021 and 2020. As of March 31, 2021, 618,004 shares remain authorized for repurchase.