Level III Core · Overview of Asset Allocation

Asset-Only vs Liability-Relative Asset Allocation Approaches

Updated 7 October 2026 · Fact-checked

Asset-only allocation sets a strategic mix from asset risk, return and correlation, without modelling liabilities. Liability-relative allocation chooses assets by how they behave against the liabilities, often targeting surplus risk. Goals-based allocation splits money into goal sub-portfolios, each with its own time horizon and required success probability.

Understand Asset-Only vs Liability-Relative Approaches

Every strategic asset allocation (SAA) starts with one question: what is the portfolio trying to achieve? The three approaches answer it differently.

Asset-only looks at assets alone. You use expected returns, volatilities and correlations to find a mix that fits the investor's risk tolerance and constraints. Mean-variance optimization is the standard tool. The investor's needs enter only through the risk budget and constraints. It suits investors with no hard liabilities, or with liabilities that are flexible, such as many endowments and foundations and wealthy individuals.

Liability-relative looks at assets against liabilities. The key measure is surplus (assets minus the present value of liabilities) or the funded ratio (assets ÷ liabilities). Risk is the risk that surplus falls, not just that assets fall. A defined benefit pension plan or insurer has fixed, contractual obligations, so this approach fits. Assets that hedge the liability, such as long-duration bonds against long-dated liabilities, are valued for how they move with the liability. A common structure is a liability-hedging portfolio that matches liability sensitivity, plus a return-seeking portfolio that aims for growth.

Goals-based looks at assets against the investor's goals. Wealth is divided into sub-portfolios, often called buckets, such as a personal (safety) goal, a market-based goal and an aspirational goal. Each has its own time horizon and a required probability of success. Safe goals get low-risk assets. Aspirational goals can take more risk. The total allocation is the sum of the buckets. It is common in private wealth, where clients think in goals, not in portfolio volatility.

The approaches differ in the definition of risk. Asset-only risk is volatility of returns. Liability-relative risk is volatility of surplus, or shortfall versus the liability. Goals-based risk is the probability of failing a specific goal. Always pick the approach that matches the client's real risk, then justify it from objectives and constraints.

Key rules to remember

Surplus: Surplus = Asset value − PV of liabilities; Liability-relative risk is the risk that this falls. Discount liabilities at a rate suited to their nature.
Funded ratio: Funded ratio = Assets ÷ PV of liabilities; Above 1 means overfunded; below 1 means underfunded. It does not tell you the risk by itself.
Surplus return: Surplus return ≈ (Change in surplus) ÷ Assets at start; Measure surplus change against beginning assets when comparing surplus performance.
Surplus variance: σ²(S) = σ²(R_A) + (L/A)² × σ²(R_L) − 2 × (L/A) × Cov(R_A, R_L); R_A and R_L are the returns on assets and on liabilities, and L/A is the ratio of liabilities to assets at the start. Surplus return is measured over beginning assets, so both changes share the same base. For given volatilities, higher correlation between assets and liabilities lowers surplus risk. Use this to explain why hedging assets cut risk.
Mean-variance utility (asset-only): U = E(Rp) − 0.5 × λ × σp²; λ is risk aversion. Liability-relative versions replace portfolio return and variance with surplus return and variance.

How to solve Asset-Only vs Liability-Relative Approaches questions

Use this sequence for any item or essay set asking which approach fits, or how to apply it.

1Identify the investor: pension, insurer, endowment, sovereign fund, bank, or individual.
2List the liabilities or goals. Are they contractual, fixed, or flexible? Are they long or short term?
3Choose the approach: asset-only if liabilities are absent or flexible; liability-relative if they are fixed and drive the risk; goals-based if the client has distinct goals with different priorities.
4Define risk the way that approach does: asset volatility, surplus volatility, or probability of missing a goal.
5If calculating, compute surplus or funded ratio first, with the correct discounting of liabilities, then apply any return or variance formula.
6State the allocation logic: liability-hedging assets for the matched part, return-seeking assets for the rest, or bucket assets by goal.
7Tie the answer to objectives and constraints, such as risk tolerance, horizon, liquidity, and regulation, in one or two sentences.
8Answer the command word exactly: if it says justify, give the reason; if it says calculate, show the number.

Quickest way: Three-question approach test

When to use it: Use when a vignette asks which approach suits a client and time is short.

Ask: are there liabilities that must be paid? If no, think asset-only.
If yes, ask: are they fixed and legally binding? If yes, liability-relative.
If the client has several goals with different importance and horizons, goals-based.
Write one sentence linking the choice to the client's main risk, and move on.

Common mistakes in Asset-Only vs Liability-Relative Approaches

Treating asset volatility as the risk measure for a pension plan.
Mean-variance habits from earlier levels carry over.
Fix: For liability-relative investors, define risk as surplus risk or shortfall versus the liabilities.
Assuming a high funded ratio means low risk.
The ratio looks like a safety measure.
Fix: Funded ratio is a level, not a risk. A plan with a high ratio but unhedged liabilities can still lose surplus quickly.
Assuming asset-only means the investor has no liabilities at all.
The name sounds absolute.
Fix: Asset-only investors may have spending needs, but the allocation is set from the asset side and constraints, not by modelling liabilities.
Thinking the goals-based total allocation is chosen first, then split into goals.
Students assume top-down construction.
Fix: Goals-based builds bottom-up: allocate each goal sub-portfolio to its required probability of success, then aggregate.
Calling any long bond a good liability hedge.
Duration is remembered but not the match.
Fix: A hedge should match the liability's sensitivity to rates and, where relevant, inflation. Mismatched duration leaves surplus risk.
Naming an approach without justifying it from constraints.
Students recall the label but skip the reasoning.
Fix: Add the link: fixed liabilities and regulation point to liability-relative; flexible spending and perpetual horizon point to asset-only.

Worked examples

Example 1

A pension plan has assets of 540 million and the present value of its liabilities is 600 million. Over the year assets rise to 580 million and the liabilities' present value rises to 650 million. Calculate the funded ratio at the start and end, and the surplus return for the year using beginning assets.

Show the solution

Start funded ratio = 540 ÷ 600 = 0.90.
End funded ratio = 580 ÷ 650 = 0.8923, about 0.892.
Start surplus = 540 − 600 = −60 million.
End surplus = 580 − 650 = −70 million.
Change in surplus = −70 − (−60) = −10 million.
Surplus return = −10 ÷ 540 = −0.0185, about −1.85%.

Answer: Funded ratio fell from 0.90 to about 0.892. Surplus return was about −1.85%. Assets grew, but liabilities grew faster, so the plan lost ground.

Example 2

A university endowment has a perpetual horizon, flexible spending and no contractual liabilities. A separate insurer holds fixed claims due in 15 years. State which approach suits each and justify briefly.

Show the solution

Endowment: no fixed liabilities, perpetual horizon, flexible spending. Risk is mainly about asset returns versus a spending target.
So asset-only fits, using risk tolerance and constraints to set the SAA.
Insurer: claims are fixed and contractual, due in 15 years.
Risk is a fall in surplus, so liability-relative fits.
Hold a liability-hedging portfolio matched to the 15-year cash flows, with any excess surplus in return-seeking assets.

Answer: Endowment: asset-only, because liabilities are flexible and the horizon is perpetual. Insurer: liability-relative, because fixed claims make surplus risk the key risk, so assets should hedge the claims.

Exam tips

Read the first lines of the vignette for the investor type. It usually decides the approach.
When a question says justify, give approach plus one client fact, such as fixed liabilities or flexible spending.
In calculations, show surplus and funded ratio separately. A correct number on its own earns credit, but show steps in case of a slip.
For goals-based questions, state each goal's horizon and required probability of success before assigning assets.
Do not name an approach and stop. Link it to objectives and constraints in your answer.

Asset-Only vs Liability-Relative Approaches: frequently asked questions

What is the main difference between asset-only and liability-relative approaches?

Asset-only sets the allocation from asset risk and return and the investor's risk tolerance. Liability-relative sets it by how assets behave against liabilities, with surplus risk as the key concern.

When is a goals-based approach used?

It is mostly used for individuals who have several goals with different horizons and priorities. Each goal gets its own sub-portfolio and a required probability of success.

Is liability-driven investing the same as liability-relative allocation?

They are closely linked. Liability-driven investing uses assets chosen to hedge or match liabilities, which is the core of a liability-relative approach.

Can an investor use more than one approach?

Yes. A plan might hedge fixed liabilities with matching assets and treat the remaining surplus with an asset-only view. Wealthy individuals may also combine goals-based buckets with asset-only thinking for the aspirational bucket.