The Smith concept of “market extent” and the Malthus idea of “resource constraint”
can be described by carrying capacity N* in the nonlinear logistic model
of population growth. When applying the ecological model to economic growth, we
need to change the name of corresponding variables. In the following discussion, we
will put the original name in theoretical ecology into brackets after the economic
variable, so that readers can clearly understand the originalmeaning and its economic
meaning.