Inflation and what it does over thirty years

A retirement lasting thirty years faces cumulative price increases that materially change what a fixed income buys. The arithmetic is worth confronting directly.

The arithmetic

At three per cent annual inflation, prices roughly double in twenty-four years.

At two per cent, they roughly double in thirty-five.

Which means someone retiring at sixty-five and living to ninety should expect that the cost of their current lifestyle will at least double during retirement, absent unusual circumstances.

A fixed nominal income therefore loses around half its purchasing power over that period, and the loss is gradual enough to be easy to ignore until it is substantial.

Where it bites hardest

Fixed pensions without adjustment. Many private pensions pay a fixed nominal amount for life, and their real value falls continuously.

Fixed annuities. The same issue. Nominal income annuities look generous at purchase and much less so twenty years later.

Bonds held to maturity. Nominal bonds pay a fixed amount and return a fixed principal, both of which lose real value.

Cash, which is the most complete exposure, since it earns little and loses purchasing power continuously.

Where it is less severe

Social Security, which receives an annual cost of living adjustment. This is one of the most valuable features of the programme and is difficult to replicate privately.

Equities, which over long periods have historically produced returns exceeding inflation, though not reliably in any given decade and with substantial volatility.

Property, where owned outright, since housing costs are largely fixed and property values have historically tracked or exceeded inflation over long periods.

This is a significant and underappreciated advantage of entering retirement without a mortgage.

Inflation-protected bonds, which adjust principal with a measure of consumer prices and provide a direct hedge.

The personal inflation rate

An important refinement.

The headline inflation measure reflects a basket of goods that may not match a retiree's spending.

Retiree spending is generally weighted more heavily toward healthcare, which has historically risen faster than general prices, and less heavily toward some categories that have risen more slowly.

An alternative index for the elderly is produced and is not used for Social Security adjustments, which has been a subject of policy debate.

The practical implication is that assuming the headline rate applies to your own spending may understate the pressure, particularly on healthcare.

What actually protects against it

Maintaining equity exposure. The counterintuitive point that runs through retirement research: portfolios that are too conservative fail more often over long horizons, because they cannot outpace prices.

Which means inflation risk and market risk trade off against each other, and eliminating one increases the other.

Delaying Social Security, which increases the size of the one income stream that adjusts automatically. A larger base receives larger absolute adjustments in every subsequent year.

Inflation-linked bonds for a portion of the fixed income allocation.

Owning your home outright, which fixes the largest single expense in nominal terms.

Spending flexibility, which allows adjustment if inflation runs above expectations.

Planning assumptions

Most retirement projections use an assumed inflation rate, and the assumption drives the result substantially.

Worth checking what rate any projection you rely on is using, and running it again with a higher figure to see how sensitive the outcome is.

A plan that works at two per cent and fails at four per cent is not a robust plan, and knowing that in advance permits adjustment while adjustment is still cheap.

The behavioural point

Inflation is the risk people most consistently underweight, because its effects are invisible in any single year.

A five per cent portfolio loss is noticed immediately. A three per cent loss of purchasing power is not noticed at all, and it recurs every year.

Which is why plans built around avoiding visible volatility frequently take on more of the risk that actually matters.

General information only, not financial advice. Past performance and historical inflation rates do not predict future results — consult a qualified adviser about your own situation.