Dear HES, I am sorry for being a little imprecise in my first query. The term monopsony (meaning a demand side monopoly) was attributed to the discussion on monopolistic competition during the 1930s (as Humberto has shown). But I was looking for earlier quotations. I know that some scholars of the school of Salamanca (e.g. Molina) were concerned with the phenomenon, but did they already use the term? And what about the mercantilists, who where concerned with "market structure" as well (if you think of J.J.Becher). Did some of them use the term? Thank you for any kind of help! Jan-Otmar Hesse