Meanness shown by mayor and spin doctor (9)
I believe the answer is:
parsimony
'meanness' is the definition.
('parsimony' can be a synonym of 'meanness')
'mayor and spin doctor' is the wordplay.
'and' says to put letters next to each other (I've seen this in other clues).
'doctor' indicates an anagram.
'mayor' put after 'spin' is 'spinmayor'.
'spinmayor' is an anagram of 'PARSIMONY'.
'shown by' is the link.
(Other definitions for parsimony that I've seen before include "avoiding excess" , "Meanness" , "economic policy" , "Reluctance to spend money unnecessarily" , "Niggardliness" .)