Table 1.

List of symbols used in the main text

Symbol	Definition
a	Age of an individual
x(a)	Non-heritable capital of an individual of age a
y(a)	Heritable capital of an individual of age a
N	Population size
zt	Heritable capital available in a population at the end of generation t
α	Exponent of x in the Cobb–Douglas production function
β	Exponent of y in the Cobb–Douglas production function
κ	β/α
P0	Production independent of personal capital
P(x, y)	Production of an individual with capital x and y
Px(x, y)	Marginal productivity of x for an individual with capital x and y
Py(x, y)	Marginal productivity of y for an individual with capital x and y
l(a)	Fraction of resources invested in social learning at age a
d(a)	Fraction of resources invested in innovation at age a
γ	Increase of x per unit of resource invested in growth
λ	Increase of y per unit of resource invested in social learning
η	Increase of y per unit of resource invested in innovation
L	Total duration of development
τ1(z)	Duration of the first development phase when the available knowledge is z
τ2(z)	Duration of the second development phase when the available knowledge is z
τ(z)	τ1(z) + τ2(z)