Conclude Panama, say, is not productive (9)
I believe the answer is:
infertile
'is not productive' is the definition.
(I've seen this before)
'conclude panama' is the wordplay.
'conclude' becomes 'infer' (inferring is a kind of concluding).
'panama' becomes 'tile' (type of hat - tile could historically mean a hat).
'infer'+'tile'='INFERTILE'
'say' is the link.
(Other definitions for infertile that I've seen before include "Barren" , "So can't father" , "Fruitless" , "Not productive" .)