Why growth is falling in all developed countries (as a long term trend)
In this post I argue that economic growth is not the normal state of affairs, it is a blip caused by the discovery of a one-off resource of non-renewable energy. The logistic equation $$ \frac{dy}{dt} = y(1-y) $$ Here's a simple model. Humans discover an exploitable but limited resource and start consuming it. The amount consumed, $y(t)$, is a function of time. The general form of the equation is $\frac{dy}{dt} = \alpha y (\beta - y)$, but if you choose the right units $\alpha$ and $\beta$ both become $1$. Why should this work, in principle? Early on, the factor $1-y$ is approximately $1$ and can be ignored. So the model states that annual consumption $dy/dt$ starts off proportional to $y$. In other words, $y$ grows exponentially at first. This could happen if exploiting the resource enables further exploitation of the resource. For example, suppose a few humans are shipwrecked on an island with 1000 trees: they take ages to cut down the ...