[mywittyname]

> Does this imply that productivity and the money supply grew at exactly the rate

Yes, and that rate of growth was probably 0.

England wasn't yet a massive trading empire. And being a small island pretty far removed from the rest of Europe, it probably didn't have a lot of wealth flowing in or out of it. And there was a functional limit to the amount of land a contingent of people could work by hand. Being a small island, all of the workable land was already being worked, so there isn't going to be a long term growth in crop yield without mechanization.

It seems the economy reached an equilibrium and remained there for a century.