3.4 Personnel expenditure

in CHF thousand   Notes   2020   2019
Wages and salaries       46,189   51,978
Social security costs       3,963   4,261
Pension costs   3.5    3,756   5,875
Other personnel expenditure       1,525   –403
Total personnel expenditure       55,433   61,711

Personnel expenditure includes charges in the amount of CHF 17,000 (2019: CHF 56,000) for employee equity incentive plans. The Book Retailing Division had varying numbers of employees on short-time work from the start of the COVID-19 lockdown in spring until the end of 2020. Compensation for short-time work of CHF 1,359,000 is recorded in the wages and salaries line item. In the prior year, the pension costs of the Security Printing Division included expenditure of CHF 1,431,000 relating to measures to increase flexibility in banknote production and the Zeiser Division reversed CHF 1,670,000 of recorded provisions through the income statement via other personnel expenditure.