Track 9 · Behaviour · lesson 7
The failure path, drawn
12 min
Track 9 · Behaviour · lesson 7
12 min
Someone starts on 30,000 a year and saves 1,200 of it. Over twenty years they do well: four promotions, one move, and an income of 90,000.
They still save 1,200 a year. Not because anything went wrong — no crisis, no dependants, no disaster. Each raise arrived, felt good for about six weeks, and then became the new floor.
This is the most common way a large income produces no wealth, and it does not require a single bad decision.
Income and spending both go up. The difference between them is the surplus, and the surplus is the only part that becomes anything.
Lifestyle inflation is not overspending. Every individual upgrade was affordable at the time it was made, and most of them genuinely improved something. The failure is that the gap never widened: each raise was absorbed before it could become a gap, so twenty years of career progress produced a better life and the same balance sheet.
The mechanism has a direction, and that is what makes it hard rather than merely careless.
Spending adjusts upward easily. A better flat, a car that starts in winter, not checking the price of a coffee — each of these is pleasant for a short period and then stops being noticeable. It becomes the reference point, and the previous level, which was fine last year, now reads as a downgrade.
Spending adjusts downward with difficulty, for exactly the reason the previous lesson gave: moving below your reference point registers as a loss, and losses are weighted heavily. So the upgrade costs a few weeks of pleasure to acquire and a real, sustained unpleasantness to reverse.
Predict
Here is the whole of it in one control. Everything else is held fixed: no starting balance, thirty years, a constant 5% return. The only thing that moves is what gets saved each year.
Compound growth
Hypothetical model, not a forecast
Grows a starting balance plus a fixed yearly contribution at a constant rate.
It assumes
It ignores
Find the yearly surplus that gets the final balance past 400,000. Note the number, and note what it is as a share of a 90,000 income.
Paid in at the end of each year, so it earns nothing in that year.
| Year | Balance | Paid in |
|---|---|---|
| 0 | 0 | 0 |
| 1 | 1.2k | 1.2k |
| 2 | 2.5k | 2.4k |
| 3 | 3.8k | 3.6k |
| 4 | 5.2k | 4.8k |
| 5 | 6.6k | 6k |
| 6 | 8.2k | 7.2k |
| 7 | 9.8k | 8.4k |
| 8 | 11.5k | 9.6k |
| 9 | 13.2k | 10.8k |
| 10 | 15.1k | 12k |
| 11 | 17k | 13.2k |
| 12 | 19.1k | 14.4k |
| 13 | 21.3k | 15.6k |
| 14 | 23.5k | 16.8k |
| 15 | 25.9k | 18k |
| 16 | 28.4k | 19.2k |
| 17 | 31k | 20.4k |
| 18 | 33.8k | 21.6k |
| 19 | 36.6k | 22.8k |
| 20 | 39.7k | 24k |
| 21 | 42.9k | 25.2k |
| 22 | 46.2k | 26.4k |
| 23 | 49.7k | 27.6k |
| 24 | 53.4k | 28.8k |
| 25 | 57.3k | 30k |
| 26 | 61.3k | 31.2k |
| 27 | 65.6k | 32.4k |
| 28 | 70.1k | 33.6k |
| 29 | 74.8k | 34.8k |
| 30 | 79.7k | 36k |
Not there yet — keep moving the controls.
The number that reaches 400,000 is somewhere around 6,000 a year. Against a 30,000 income that is a fifth of it and hard. Against a 90,000 income it is under 7%, and it is the amount that four promotions could have produced without anybody living worse than they did at the start.
That is the actual cost of the ratchet. Not the coffees. The seven percent that never became a gap.
Suppose instead the surplus stays at 1,200 forever, and the plan is to make up the difference with returns. Same thirty years, same target.
Compound growth
Hypothetical model, not a forecast
Grows a starting balance plus a fixed yearly contribution at a constant rate.
It assumes
It ignores
Leaving the surplus at 1,200, find the annual return that reaches the same 400,000.
| Year | Balance | Paid in |
|---|---|---|
| 0 | 0 | 0 |
| 1 | 1.2k | 1.2k |
| 2 | 2.5k | 2.4k |
| 3 | 3.8k | 3.6k |
| 4 | 5.2k | 4.8k |
| 5 | 6.6k | 6k |
| 6 | 8.2k | 7.2k |
| 7 | 9.8k | 8.4k |
| 8 | 11.5k | 9.6k |
| 9 | 13.2k | 10.8k |
| 10 | 15.1k | 12k |
| 11 | 17k | 13.2k |
| 12 | 19.1k | 14.4k |
| 13 | 21.3k | 15.6k |
| 14 | 23.5k | 16.8k |
| 15 | 25.9k | 18k |
| 16 | 28.4k | 19.2k |
| 17 | 31k | 20.4k |
| 18 | 33.8k | 21.6k |
| 19 | 36.6k | 22.8k |
| 20 | 39.7k | 24k |
| 21 | 42.9k | 25.2k |
| 22 | 46.2k | 26.4k |
| 23 | 49.7k | 27.6k |
| 24 | 53.4k | 28.8k |
| 25 | 57.3k | 30k |
| 26 | 61.3k | 31.2k |
| 27 | 65.6k | 32.4k |
| 28 | 70.1k | 33.6k |
| 29 | 74.8k | 34.8k |
| 30 | 79.7k | 36k |
Not there yet — keep moving the controls.
The return needed is somewhere close to 14% a year, every year, for thirty years. That is not a target anybody can choose. The 6,000 a year is.
This is the reason the behaviour track exists at all: one of these two levers is under your control and the other is a wish, and the one under your control is the one being quietly disposed of by the ratchet.
Check
Nothing here says a rising income should be entirely converted into a rising balance. That would be a strange way to live, and the whole last track of this course is about what the money is for.
The distinction that survives scrutiny is between spending that permanently raises the floor and spending that does not. A cost that recurs every month forever — a larger fixed housing cost, a subscription, a car payment — takes a slice of every future raise as well as this one. A one-off does not.
Two people spending the same amount this year can be in completely different positions next year, depending on which kind they bought.