Equation 21 · Part 2 · Who Builds 2100? The Demographic Engine of Technological Evolution
subscript
subscript
What this part means
The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.
Its job in the formula
A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.
Full expression→subscript→Article meaning
The passage around this formula
The two right-hand boxes both depend on the Aghion-Jones-Jones mechanism actually materializing at the scale their formal model allows for, which Section 5 was careful to label a named, live argument rather than a documented fact. If it does materialize, the difference between the top-right and bottom-right boxes — whether population is also growing or is instead the IHME-scale decline — matters much less than in the human-bound cases, because a large enough term dominates the sum in the numerator of the growth relation regardless of what is doing. That is precisely Aghion, Jones, and Jones’s point about their own model: sufficiently complete automation of the idea-production…
Learn the underlying idea
A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
Open the illustrated subscripts: which member of a family? guide →
Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.