26Post-employment benefits include items such as the following:

26 Post-employment benefits include items such as the following:
(a) retirement benefits (eg pensions and lump sum payments on retirement); and
(b) other post-employment benefits, such as post-employment life insurance and post-employment medical care.
Arrangements whereby an entity provides post-employment benefits are post-employment benefit plans. An entity applies this Standard to all such arrangements whether or not they involve the establishment of a separate entity to receive contributions and to pay benefits.
27 Post-employment benefit plans are classified as either defined contribution plans or defined benefit plans, depending on the economic substance of the plan as derived from its principal terms and conditions.
28 Under defined contribution plans the entity’s legal or constructive obligation is limited to the amount that it agrees to contribute to the fund. Thus, the amount of the post-employment benefits received by the employee is determined by the amount of contributions paid by an entity (and perhaps also the employee) to a post-employment benefit plan or to an insurance company, together with investment returns arising from the contributions. In consequence, actuarial risk (that benefits will be less than expected) and investment risk (that assets invested will be insufficient to meet expected benefits) fall, in substance, on the employee.
29 Examples of cases where an entity’s obligation is not limited to the amount that it agrees to contribute to the fund are when the entity has a legal or constructive obligation through:
(a) a plan benefit formula that is not linked solely to the amount of contributions and requires the entity to provide further contributions if assets are insufficient to meet the benefits in the plan benefit formula;
(b) a guarantee, either indirectly through a plan or directly, of a specified return on contributions; or
(c) those informal practices that give rise to a constructive obligation. For example, a constructive obligation may arise where an entity has a history of increasing benefits for former employees to keep pace with inflation even where there is no legal obligation to do so.