I thought the famous story often retailed about Samuelson's thesis defense
was that at the end of the session one of his committee members, I thought
it may have been Arthur Smithies asked Samuelson, "Did WE [the faculty
committee] pass?"  This story which of course may well be apocryphal does
suggest Harvard did have dissertation committees or at least that there
were dissertation defense sessions in which faculty were present and
rendered a verdict.

Actually I would be interested in knowing what the answer
is to Roy Weintraub's query. I would think that Harvard
catalogues and announcements from the relevant time
period might indicate what the official policy was of
the degree granting body of Harvard, whether the Economics
department or say the arts and sciences graduate faculty
which may have set the policy regarding dissertation committees
and dissertation defenses etc.

David Mitch