ACTL10001 Chap.12 Superannuation and Reverse Mortgages
Superannuation and Reverse Mortgages
Superannuation designs allocate investment, longevity and funding risk differently. Defined contribution fixes the contribution formula and lets the member account determine retirement value. Defined benefit fixes a benefit formula and leaves the sponsor responsible for funding the promise under the plan rules. Reverse mortgages combine loan accumulation with uncertain exit timing and property value.
A no negative equity guarantee becomes valuable when debt exceeds sale proceeds, so its cost depends on longevity or occupancy, interest and housing outcomes. Actuarial analysis connects these uncertain events to cashflows, funding and risk ownership.
What this chapter covers
- 01
Defined contribution plans
- 02
Defined benefit plans
- 03
Investment risk allocation
- 04
Longevity risk
- 05
Funding valuations
- 06
Reverse mortgage balances
- 07
Property value uncertainty
- 08
No negative equity guarantees
Worked example · free
Allocate an investment shock
- 1The account loses $12,000 and falls to $108,000.
- 1The defined contribution member directly bears that asset loss through the account value.
- 1A defined benefit formula does not automatically fall by 10%; the shock can instead worsen the sponsor funding position.
Key terms
- Defined Contribution
- A retirement arrangement that defines contributions while account outcomes depend on investment experience.
- Defined Benefit
- A retirement arrangement promising a benefit determined by a formula, creating sponsor funding obligations.
- Funding Position
- The relationship between plan assets and the value of promised benefits.
- Longevity Risk
- The risk that people survive longer than assumed and receive benefits for more time.
- Reverse Mortgage
- A loan secured on a home whose repayment is commonly deferred until a later exit event.
- Equity Guarantee
- Protection limiting repayment to property proceeds when a reverse mortgage balance exceeds home value.
Superannuation and Reverse Mortgages FAQ
What is defined in each superannuation design?
Defined contribution specifies the contribution arrangement, while defined benefit specifies a benefit formula. This determines who initially bears investment and funding deviations after contributions enter the arrangement.
Why are actuaries important in defined benefit plans?
They value future promised payments, select and test assumptions, assess funding and advise on contributions and risk management for the sponsor over the plan's horizon.
What drives a reverse mortgage guarantee?
Longer occupancy, faster loan interest and weaker property values can make the loan more likely to exceed sale proceeds at the exit event, creating a guarantee shortfall.
Why is longevity relevant to housing credit?
Repayment may be delayed while the borrower remains in the home, allowing interest to compound and changing the distribution of the eventual guarantee shortfall at exit.
What creates the contingent cost in a reverse-mortgage guarantee?
The cost arises when the accumulated loan exceeds property proceeds at the uncertain exit date. Loan interest, property growth, longevity and borrower behaviour jointly affect whether that shortfall branch occurs and how large it becomes.
Why does longevity affect retirement arrangements in different ways?
A defined-contribution member may need an individual account to finance more retirement years, while a defined-benefit sponsor or annuity provider may owe benefits for longer than assumed. The direction is linked to who promises the income. State the benefit design and risk bearer before describing longevity as favourable or adverse.
Inflation and benefit indexation then determine how those extra years translate into purchasing power or sponsor cost. Contribution adequacy affects the member outcome before retirement begins.
Exam move
Compare retirement designs using promise, account, risk bearer and actuarial role. Trace one market or longevity shock through both designs and explain who responds. For reverse mortgages, draw loan balance and property value evolving until an uncertain exit date, then identify the shortfall branch. Avoid treating average exit age or house growth as certain.
Finish each answer by naming the party that holds the adverse outcome and the assumptions requiring monitoring. Construct a risk-allocation table with rows for investment return, longevity, inflation, salary and contribution adequacy. For each row, identify how the outcome enters a defined-contribution account and how it affects a defined-benefit sponsor's funding position.
Distinguish the benefit formula from the assets held to support it: a market fall can reduce plan assets even when the promised formula is unchanged. Trace a shock through member income, sponsor contributions and actuarial valuation rather than stopping at the asset return. For reverse mortgages, place property value and accumulated loan balance on the same exit-date diagram.
The guarantee payment is the positive shortfall when debt exceeds proceeds, not the full loan balance. Vary loan interest, property growth, initial advance and exit timing one at a time and predict the direction of guarantee exposure. Then test combined scenarios while stating any assumed dependence. Treat exit as contingent on survival, care entry, move-out or sale conditions instead of using one certain average date.
Include a zero-shortfall branch so expected value accounts for outcomes where property covers the debt. End both retirement and housing answers by naming the stakeholder who bears each adverse outcome. A numerical projection is incomplete without the assumptions being monitored and the mechanism transferring risk between member, sponsor, lender or guarantor.
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