Risk & Allocation
Capacity for loss is arithmetic; tolerance is a feeling
How much risk you can take and how much you want to take are different questions. Only one of them has an answer you can calculate.
This is less a set of instructions about capacity for loss than an argument, and it is worth saying so at the start.
The argument in brief
- Where capacity and tolerance disagree, capacity is the binding constraint.
- Other income, flexibility and time all raise capacity.
- Each goal has its own capacity, and different answers are correct.
Two separate questions
Risk tolerance describes how much volatility you are willing to live with, and it is a matter of temperament and experience. Capacity for loss describes how much you could absorb before the goal became unreachable, and it is a matter of arithmetic.
A person can be entirely comfortable with volatility and have almost no capacity to withstand it, and the reverse happens too. Most questionnaires measure the first far more thoroughly than the second, which is a well-known weakness of the format. Where the two disagree, capacity binds, because feelings do not change what a portfolio is able to fund.
What determines capacity
The size of shortfall you could tolerate in the goal is the first input, and for some goals that shortfall is close to zero. Time remaining matters, because a longer horizon allows continued contributions to repair damage a fall has already done. Other income and other assets raise capacity, since a portfolio funding part of a goal can absorb more than one funding all of it.
For most people, flexibility raises it too, because a goal that can be delayed or reduced is a goal with genuine slack built into it. None of these is about how you feel, and every one of them can be estimated well enough to be useful.
Where capacity is low and gets ignored
Money for a house deposit within a few years has almost no capacity for loss, whatever the buyer's appetite for risk. A portfolio funding essential spending in retirement has less capacity than one funding discretionary spending on top of a pension. Somebody with no emergency buffer has low capacity across everything, because any shock at all forces a sale.
In practice, self-employed income with no sick pay reduces capacity in a way that never appears on any risk questionnaire. These situations are common, and the questionnaires that miss them are widely used, which is worth knowing about.
Where capacity is higher than people assume
A young contributor with decades ahead and secure income has high capacity even if the balance feels large to them. Somebody whose essential spending is fully covered by guaranteed income has high capacity in whatever portfolio remains.
An inheritance or a property owned outright can raise capacity substantially without changing anybody's stated tolerance at all. People in these situations frequently hold conservative portfolios chosen from feeling rather than from the arithmetic.
That is a legitimate choice, provided it is made knowing which of the two questions it is actually answering.
Estimating it roughly
Write down the goal, the date, the amount needed and how much of that amount the portfolio is responsible for funding. Then ask what size of fall could occur without the goal becoming unreachable, given the contributions still to come. The answer will be approximate and is still far more informative than a score derived from five multiple-choice questions.
For most people, doing it separately for each goal produces different answers, which is the correct outcome rather than an inconsistency. Anything turning on precise figures for your own situation is a job for regulated advice in your own country.
Using both answers
Take the lower of what you can absorb and what you can live with, because either constraint alone is enough to break a plan. Exceeding capacity risks the goal; exceeding tolerance risks abandonment, and abandonment tends to happen at the worst possible moment. Where tolerance binds, that is worth revisiting as experience accumulates, since tolerance is at least partly learned.
The useful part is this: where capacity binds, the honest options are reducing risk, extending the horizon or adjusting what the goal actually is. Writing down which constraint is binding turns the annual review into a check rather than a fresh argument with yourself.
The takeaway
Tolerance decides whether you hold on. Capacity decides whether holding on was enough.
The version you keep doing is the version that works.
Questions readers ask
Which matters more, capacity or tolerance?
Capacity sets the limit and tolerance decides whether you will stay invested. A plan has to respect both, so the lower of the two governs.
Can capacity for loss change?
Yes, and often faster than tolerance does. A job change, a birth, an inheritance or a shortening horizon all move it without changing how you feel.
