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Equation 11 · Part 1 · Who Builds 2100? The Demographic Engine of Technological Evolution

Symbol g_A

gA=gC+gS1−ϕg_A = \frac{g_C + g_S}{1-\phi}
gAg_A

What this part means

gAg_A is part of the quantity the equation computes from the expression on the right.

Its job in the formula

gAg_A is part of the quantity the equation computes from the expression on the right.

The passage around this formula

The named argument belongs to Philippe Aghion, Benjamin F. Jones, and Charles I. Jones, whose 2017 National Bureau of Economic Research paper works out formally what happens when artificial intelligence automates tasks inside the idea-production function itself, rather than only inside the production of ordinary goods. Their result, worked through with an idea-production function in which a fraction of research tasks can be automated, is that in the case without automation their model collapses to exactly the semi-endogenous relation from Section 3 above — the growth rate of ideas proportional to the growth rate of the human research population, discounted by diminishing returns — matching…

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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.

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Sources cited in the surrounding passage

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