An employee of a public Canadian corporation receives an option to purchase 1,000 of her employers common shares at $23 per share in March of the current year. At this time the fair market value of the stock is $21 per share. In August, when the fair market value is $27 per share, she exercises the option to purchase 1,000 shares. In December, she sells the shares when the fair market value is $30 per share.

By what amount do these transactions increase the employee's employment income, and when is the employment income inclusion recognized?