potential output

Every economy has a kind of natural pace — the amount it can produce when its people, machines, and resources are all being used at their normal, sustainable rate, without overstraining anything. It is not the absolute maximum you could squeeze out in a frantic push, but the comfortable, repeatable level. That sustainable level of production is called potential output. It is the trend the economy hovers around as the business cycle pushes it temporarily higher or lower.

Precisely, potential output is the real GDP an economy would produce if labour and capital were employed at their normal long-run rates — which still leaves some 'natural' unemployment from people switching jobs and skills not matching openings. It is determined by the real fundamentals: the size and skill of the workforce, the stock of capital, and the level of technology. It grows over time as those improve, which is exactly why economies trend upward over decades. Crucially, potential is a supply-side idea: it is about how much can be made, not how much is being spent. In the AD-AS model, potential output is where the vertical long-run aggregate supply curve sits.

Potential output matters because it is the benchmark against which booms and busts are measured: the output gap is simply actual output minus potential. It tells policymakers whether there is slack to grow into or whether pushing harder will just cause inflation. The honest caveat — and it is a big one — is that potential output is unobservable. We never see it directly; we infer it with models, and the estimates are uncertain, vary across methods, and get revised. Two careful economists can look at the same economy and disagree about what its potential is.