(12) Employee Stock Purchase Plan In September 1996, Forrester adopted the 1996 Employee Stock Purchase Plan (the Stock Purchase Plan), which provides for the issuance of up to 400,000 shares of common stock. The Stock Purchase Plan is administered by the Compensation Committee. With certain limited exceptions, all employees of Forrester who have completed six months or more of continuous service in the employ of Forrester and whose customary employment is more than 30 hours per week, including officers and directors who are employees, are eligible to participate in the Stock Purchase Plan. Purchase periods under the Stock Purchase Plan are generally six months in length and commence on each successive July 1 and January 1. During each purchase period under the Stock Purchase Plan, the maximum number of shares of common stock that may be purchased by an employee is limited to the number of shares equal to $12,500 divided by the fair market value of a share of common stock on the first day of the purchase period. An employee may elect to have up to a maximum of 10% deducted from his or her regular salary for the purpose of purchasing shares under the Stock Purchase Plan. The price at which the employee’s shares are purchased is the lower of (a) 85% of the closing price of the common stock on the day that the purchase period commences, or (b) 85% of the closing price of the common stock on the day that the purchase period terminates. Shares purchased by employees under the Stock Purchase Plan are as follows: Accrued Expenses. Accrued expenses as of December 31, 1999 and 2000 consist of the following (in thousands): Allowance for Doubtful Accounts. A roll-forward of the allowance for doubtful accounts as of and for the years ended December 31, 1998, 1999, and 2000 is as follows (in thousands): (13) Certain Balance Sheet Accounts Shares Purchase Purchase Period Ended Purchased Price June 30, 1998 37,626 $ 9.83 December 31, 1998 25,030 $17.27 June 30, 1999 38,570 $10.61 December 31, 1999 49,316 $10.89 June 30, 2000 34,238 $27.94 December 31, 2000 28,575 $42.55 1999 2000 Payroll and related $4,763 $ 8,320 Other 4,684 9,064 $9,447 $17,384 1998 1999 2000 Balance, beginning of period $ 325 $ 400 $ 580 Provision for doubtful accounts 375 904 1,246 Additions arising from acquisitions (Note 2) — 80 47 Write-offs (300) (804) (580) Balance, end of period $ 400 $ 580 $1,293