Definition
Cost of income is the capital required today to produce one dollar of lifetime annual income, evaluated against a frictionless actuarial benchmark, and is the foundational analytical unit of the Longevity Standard framework.
Why it matters
Most retirement analysis starts with “what will my savings produce?” and works forward to an answer. Cost of income inverts the question to “what does the income I need cost to produce?” and works backward. The inversion is what makes lifetime income arrangements comparable across very different structures on a single unit.
How it works
Cost of income expresses the capital required today for each dollar of lifetime annual income under a given arrangement, measured against the frictionless actuarial benchmark. Every lifetime income arrangement — self-managed drawdown, SPIA, deferred income annuity, direct pool, variable annuity with guaranteed living benefit — can be reduced to this unit. The resulting figure is a single number per arrangement that reflects the combined effect of the arrangement's cost structure, its treatment of mortality credits, the prevailing interest rate environment, and any deferral or other structural features.
In practice
Cost of income is the frame that matches how retirement income planning actually happens. You identify what your essential expenses are, what Social Security will cover, and the gap between the two. The question is what it costs to fund that gap with lifetime income — not what your account balance happens to produce. A professional can run your income target through several arrangements and show you each one's cost side by side, against the frictionless benchmark, so that five quotes with five different structures become a single comparison. When a product manufacturer cannot produce a cost-of-income comparison against the benchmark, that itself is information.
In the Longevity Standard Framework
Cost of income is one of the four core terms of the Longevity Standard framework and the canonical analytical unit in which every published finding is stated. Two complementary frames operate on the cost-of-income unit: the cost view fixes the income target and compares capital required across arrangements; the income view fixes the savings balance and compares income produced. Both frames use the frictionless pool as the benchmark and solo drawdown as the baseline, with realized value expressing how much of the theoretical benefit each arrangement delivers. The cost-of-income frame makes the four claim properties commensurable in practice — arrangements with very different risk-sharing, adjustment-mechanism, liquidity, and cost-structure profiles can still be compared on the single axis of what it costs to produce a dollar of lifetime income.
Related terms
- Frictionless pool
- Solo drawdown
- Realized value
- Cost view
- Income view
- Insurer load
- Actuarial present value
- Payout rate