We are living longer today — a positive development. Yet each year, inflation quietly erodes the purchasing power of our savings. These two trends — the gradual rise in longevity and persistent inflation — together create an invisible dual erosion that can undermine even the most carefully constructed retirement plans.

The Slow Attrition

  • Average inflation of 1% per year reduces purchasing power by approximately 26% over 30 years.
  • At 2% per year, the reduction reaches approximately 45%.
  • At 3%, erosion stands at approximately 64% over the same period.

Meanwhile, life expectancy continues to lengthen: if we expect to live to 90, it means exposing our savings to 25 years of erosion rather than 20.

These two forces — growing longevity and inflation — are interconnected: the more years you live, the more inflation erodes the real value of your savings. This phenomenon has been described as “retirement entropy”.

A Concrete Example: Fixed Income of €1,500

Imagine receiving a non-indexed pension of €1,500 per month and expecting to live for 30 years. Here is the real purchasing power after three decades:

  • Annual inflation 1% → real value approximately €1,200
  • Inflation 2% → approximately €920
  • Inflation 3% → only €670

Not only does the nominal figure remain fixed, but after 30 years it risks becoming insufficient to cover essential expenses — precisely when you will need it most.

The Fundamental Weakness: Nominal ≠ Real

Many retirement plans stop at a nominal analysis: “Yes, the money will last until age 90.” Yet this view overlooks a crucial fact: how much that money will actually be able to purchase in the future. An income that appears adequate today may become insufficient in 20–30 years, once inflation has driven up the cost of many necessities: medicines, utility bills, daily care.

Strategies for Protection

To counter this dual erosion, it is essential to adopt a dynamic retirement strategy:

  • Inflation-linked annuities — costly, but they protect purchasing power.
  • “Real” portfolio — investments in equities, real estate, or inflation-linked securities.
  • Flexible decumulation — withdrawals that adapt to real needs and inflation.
  • Dedicated terminal reserve — a specific fund to cover the final years of life.

These solutions do not aim for perfection, but for preserving the real value of capital over time.

A New Metric: Residual Annual Purchasing Power

It is no longer sufficient to know “whether the money will last until age 90”. The real question is:

“How much will I be able to continue spending each year, up to the age of 90 or 95?”

What is needed is a metric that integrates both the duration of life and the real value of money — the so-called residual annual purchasing power. This measure answers the question: “Will that money still fulfil its function in the more advanced years of life?”

In Conclusion

  • Growing longevity extends the time horizon that must be covered.
  • Inflation gradually erodes the value of savings.
  • A sustainable retirement plan must combine real duration and protected value over time.

This is not merely about living longer, but about living well and with financial independence. An objective that demands awareness, appropriate tools, and retirement planning genuinely commensurate with the time we shall truly live.