9.	Payroll and related benefits


Million US dollar	2018			2017			2016
Wages and salaries		(4 726	)		(4 884	)		(4 404	)
Social security contributions		(698	)		(699	)		(647	)
Other personnel cost		(708	)		(762	)		(580	)
Pension expense for defined benefit plans		(193	)		(196	)		(194	)
Share-based payment expense		(353	)		(359	)		(228	)
Contributions to defined contribution plans		(116	)		(118	)		(77	)

Payroll and related benefits		(6 794	)		(7 018	)		(6 130	)

The number of full time equivalents can be split as follows:


	2018		2017		2016
AB InBev NV (parent company)		180		215		225
Other subsidiaries		172 423		182 700		206 408

Total number of FTE		172 603		182 915		206 633

The 2018 reduction in FTE mainly results from the combination of the AB InBev Russia and Ukraine businesses under AB InBev Efes. As a result of the transaction, AB InBev stopped consolidating its Russia and Ukraine businesses and accounts for its investment in AB InBev Efes under the equity method as of that date. See also Note 6 Acquisitions and disposals of subsidiaries.

The 2017 increase in payroll and related benefits is mainly due to the full year reporting of the retained operations following the combination with SAB, whereas the reduction in FTEs mainly results from the disposals completed during the year.