I've always thought that the terminology arose out of generalising the
Ricardian notion of the intensive margin in his rent theory to all factors
of production. Hence because marginalism was an approach which generalised
Ricardo, 'neo-classical' was an appropriate terminology. But I haven't the
faintest recollection where I learnt/read this, except that it was as a
graduate student in the early '70s.
Simon
Dr. Simon Mohun,
Dept of Economics,
Queen Mary and Westfield College,
Mile End Road,
London E1 4NS,
UK
Tel: +171-975-5089; Fax: +181-983-3580