Equation 1 · Part 9 · Who Builds 2100? The Demographic Engine of Technological Evolution
Denominator: 1-phi
What this part means
The complete quantity below the fraction bar; it must be nonzero for this division.
Its job in the formula
1-phi occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.
Full expression→Denominator: 1-phi→Article meaning
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…
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.
Open the illustrated fractions: division written vertically guide →
Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.