8. Earnings (Loss) Per Share	9 Months Ended
Sep. 30, 2019
Net income (loss) per share:
Earnings (Loss) Per Share	Basic earnings (loss) per share is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of common shares, except for periods with a loss from operations. Diluted earnings (loss) per share reflects additional common shares that would have been outstanding if dilutive potential shares of common stock had been issued. Potential shares of common stock that may be issued by the Company include shares of common stock that may be issued upon exercise of outstanding stock options. Under the treasury stock method, the unexercised options are assumed to be exercised at the beginning of the period or at issuance, if later. The assumed proceeds are then used to purchase shares of common stock at the average market price during the period. Basic and diluted loss per common share for the three-month period ended September 30, 2019 was $0.01, and diluted loss per common share excludes the effects of 496,319 common share equivalents, since such inclusion would be anti-dilutive. Basic earnings per common share for the three-month period ended September 30, 2018 was $0.02. Diluted earnings per common share for the three-month period ended September 30, 2018 was $0.02 and includes the dilutive effects of 724,958 common share equivalents. Basic and diluted loss per common share for the nine-month period ended September 30, 2019 was $0.11, and diluted loss per common share excludes the effects of 496,319 common share equivalents, since such inclusion would be anti-dilutive. Diluted earnings per common share for the nine-month period ended September 30, 2018 was $0.05 and includes the dilutive effects of 724,958 common share equivalents. The common share equivalents consist of common shares issuable upon exercise of outstanding stock options.

8. Earnings (Loss) Per Share

9 Months Ended

Sep. 30, 2019

Basic earnings (loss) per share is calculated by dividing net income (loss) attributable to common stockholders by the weighted-average number of common shares, except for periods with a loss from operations. Diluted earnings (loss) per share reflects additional common shares that would have been outstanding if dilutive potential shares of common stock had been issued. Potential shares of common stock that may be issued by the Company include shares of common stock that may be issued upon exercise of outstanding stock options. Under the treasury stock method, the unexercised options are assumed to be exercised at the beginning of the period or at issuance, if later. The assumed proceeds are then used to purchase shares of common stock at the average market price during the period.

Basic and diluted loss per common share for the three-month period ended September 30, 2019 was $0.01, and diluted loss per common share excludes the effects of 496,319 common share equivalents, since such inclusion would be anti-dilutive. Basic earnings per common share for the three-month period ended September 30, 2018 was $0.02. Diluted earnings per common share for the three-month period ended September 30, 2018 was $0.02 and includes the dilutive effects of 724,958 common share equivalents. Basic and diluted loss per common share for the nine-month period ended September 30, 2019 was $0.11, and diluted loss per common share excludes the effects of 496,319 common share equivalents, since such inclusion would be anti-dilutive. Diluted earnings per common share for the nine-month period ended September 30, 2018 was $0.05 and includes the dilutive effects of 724,958 common share equivalents. The common share equivalents consist of common shares issuable upon exercise of outstanding stock options.