Check out Figure 2[a]

https://people.bu.edu/chamley/HSFref/Allen11.pdf

(Figures 4-5 for Newcastle)

>Between 1500 and 1600, the population of London grew from about 50,000 to 200,000 in response to the trade-induced growth in labour demand. During the Commonwealth, Cromwell initiated an active imperial policy, and it was continued through the eighteenth century

Fig 6! (guess there's a lot to be said for "like taking coals to Newcastle")

this conversation inspired me to think about the existence of a "natural" conservation law that could be associated with our fave isoquants (& figure 7!) :)