The clients we have worked with for twenty-five years or more are sometimes the most instructive. Many of them do not feel much different from when we first met them. They have left full-time work, but they have not left the picture. A number are consulting two or three days a week. Some moved into governance roles after finishing their main careers and have stayed there for a decade or more. We have clients in their seventies who have ridden the Tour Aotearoa more than once.
This is not anecdote. The IMF has formalised what many of us observe in practice. A seventy-year-old today has the same cognitive ability as a fifty-three-year-old did in 2000. A retirement lasting twenty-five to thirty years is no longer unusual. Most financial plans were not designed for that.
Longer does not mean the same for longer
One of the most useful things international ageing research has clarified is the distinction between life expectancy and healthy life expectancy. Many people now experience a prolonged middle period of relative health and independence, followed by a shorter but more intensive phase of decline.
From a financial planning perspective, this is important. Early retirement years are often more expensive than people expect. People travel, help family members, renovate, and pursue things they put off during working life. Later-life costs tend to be lumpy and harder to forecast: care, accommodation changes, health events. They do not happen on a schedule.
Plans built on smooth averages frequently misrepresent how money is actually used. Longevity introduces shape into retirement, not just extra years. Planning for the shape is more useful than planning for the average.
The problem with a single number
The IMF's longevity research highlights something that is easy to state but important to absorb: longer lives increase dispersion. Two people who retire at sixty-five with identical financial positions may have very different experiences by age eighty. One remains healthy, keeps working part-time, and spends modestly. Another faces significant health costs by seventy-five and needs care by eighty.
The longer the retirement, the wider the gap between those outcomes becomes. A plan built around a single typical path becomes less reliable the further out it projects.
This is why we argue that resilience is more valuable than precision. Understanding how your position changes under different assumptions is more useful than chasing one right number, because that number will be wrong in ways you cannot predict at the outset.
The most useful financial plan for a long retirement is not the one with the most accurate forecast. It is the one that works when circumstances change, because they will.
Doing nothing is sometimes the right move
This is one of the more counter-intuitive insights that long-horizon planning produces. When retirement lasted a decade, early decisions had limited long-term impact. In a thirty-year retirement, early choices compound. Acting too quickly can do more damage than waiting.
Common problems arise when people reduce spending prematurely out of anxiety, overreact to short-term market movements, or lock themselves into decisions that are difficult to reverse. Research into decision-making under uncertainty consistently shows that the option to delay irreversible choices has real value. Keeping your choices open while the picture becomes clearer is not procrastination. It is often sound strategy.
Where NZ Super fits
NZ Superannuation provides a floor, not a plan. For someone retiring at sixty-five with a twenty-five-year planning horizon, it covers a portion of essential spending. The exact proportion depends on household structure, location, and lifestyle, and in most cases it leaves a meaningful funding gap that savings, KiwiSaver, and other assets need to cover.
The less certain question is what NZ Superannuation will look like in ten or twenty years. There are credible scenarios in which eligibility age rises, or income testing is introduced for higher earners. None of this has been legislated, but these are not remote possibilities. A plan built around current NZ Superannuation settings carries a risk that a plan built around what NZ Superannuation does, rather than what it currently pays, does not.
Planning as a process
The approaches that work best over long retirements share common characteristics. They explore ranges of outcomes rather than single forecasts. They make assumptions explicit rather than hidden. And they are revisited as life changes, rather than filed away.
The purpose is not to predict the future accurately. It is to provide a framework for making good decisions when the future turns out differently than expected, which over twenty-five to thirty years, it inevitably will.
Our white paper, Seventy Is the New Fifty, goes through all of this: what longer lives mean for spending patterns, how dispersion changes the value of flexibility, why doing nothing can be the right call, and how NZ Superannuation fits into a long-horizon plan. It draws on IMF longevity research and on what we see in practice with clients who are navigating exactly this.
If you are within ten years of stopping full-time work, or have already stopped, the white paper is worth reading before your next planning conversation.
Link to download below.
