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Equation 1 · Part 8 · Who Builds 2100? The Demographic Engine of Technological Evolution

Numerator: λ n

gA=λn1−ϕg_A = \frac{\lambda n}{1-\phi}
λn\lambda n

What this part means

The complete quantity above the fraction bar.

Its job in the formula

λ n occurs above the fraction bar. The numerator is divided by the entire denominator below it.

The passage around this formula

Semi-endogenous growth theory, the framework Jones developed and that his 2022 Annual Review of Economics piece surveys, formalizes this into a relationship between population growth and the long-run growth rate of ideas [ 4 ] . Population enters the idea-production function as the stock of people available to search the technological fitness landscape for improvements, and because ideas are non-rival — one firm’s discovery of a better transistor layout does not use up the possibility for another firm to discover a different one — expanding that search population raises the rate of discovery roughly in proportion to its own growth, discounted by how much duplicated effort dilutes the return…

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Learn the underlying idea

A fraction a/b means a divided by b. The top number is the numerator; the bottom number is the denominator, and it cannot be zero.

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Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.