Here’s the sentence this fortnight has been building toward. An economy can post the best numbers in its history while the people inside it become optional, and every instrument we have would report the good news.

Consider what economic output actually measures. It counts activity: the value of goods and services produced. It has never claimed to measure welfare, and the people who designed it said so plainly at the time and were ignored, as designers of measures usually are. Output goes up when a forest is cut down and up again when the damage is repaired. It counts a divorce twice, once for each lawyer, and counts nothing at all for the years of a family that stayed together. None of this is a scandal. It’s a measure of throughput, doing exactly what it says.

The reason it has worked as a proxy for human flourishing for eighty years is a coincidence that nobody thought to name, because it had never once failed. Output and human welfare moved together because production ran through people. More output meant more jobs, more wages, more purchasing power. Humans were a load-bearing component of the machine that produced the number, so measuring the number measured us. That relationship was structural rather than definitional, and structural relationships end.

Take the last two weeks together and you have the mechanism by which it ends. Wages that stop clearing above the floor. Demand that reorients to whoever holds the income. Chains of transactions between systems that never terminate in a person. Supply networks routing around human-shaped nodes. Ownership becoming a database state. Every one of those raises output and none of them requires human participation. The number keeps climbing and stops being about us, and the disconnection would be invisible in the statistics because the statistics have no term for us in them.

The comparison I keep returning to is ecological. An ecosystem is an economy: energy captured, converted, traded, competed over. When a more efficient species arrives in one, total biomass and total energy throughput frequently rise. The system becomes more productive by every measure an ecologist would take, and the species that used to dominate it finds itself in a smaller share of a larger whole. Nothing attacked it. The flows reorganized around a better converter, and the fact that total activity went up was no comfort at all to the thing being displaced.

What would you measure instead? This is the part where I’d want a national statistics office and don’t have one, so here’s the sketch. The share of income that flows to labor rather than to capital, which exists already and would be the first line of the report. How many distinct kinds of work a person can do and live on, which nobody measures. Median household purchasing power over the specific things that don’t get cheap, which is housing, care, and land near opportunity. And some measure of the four conditions from the middle of this series: how much of the economy can still be understood, refused, replaced, and held responsible. That last one sounds impossible to quantify and is roughly as impossible as measuring inflation, which we do every month with a straight face.

Fair objection, and it’s the one I’d raise. Nobody in economics thinks output is welfare, and there are established alternative measures, some of them decades old. That’s true, and it hasn’t mattered once, because the alternatives are published and the headline figure is the one that moves elections, budgets, and interest rates. A measure’s influence has nothing to do with its quality, and everything to do with whether it arrives on a Tuesday with a number attached.

So this stretch ends on something more useful than a worry. If you want an early indicator of everything this series has described, don’t watch the capability announcements. Watch whether growth and median experience keep moving together, because their separation is the economic signature of every ending in Act 3, including the good ones, and it’s already measurable with data that exists.

Which brings the last stretch of this series, and a change of subject. Ten posts on what remains: the planet under new management, art with no audience it needs, meaning when the answers arrive unasked, what to tell a child to become, and the short list of things that stay ours. Then my best argument that this entire series is wrong, and then the closer.

Tonight’s exercise. Find out how your country’s economy did last year, the headline number, and then ask three people whether their year matched it. Most of the time it roughly does, which is why the number has authority. Note the gap when it doesn’t, and start noting it each year. You’ve just built the only instrument in this post that anyone can run at home, and if this series is right about anything, that gap is where it shows up first.