One new coin setter has taken for carrot (9)
I believe the answer is:
'taken for carrot' is the definition.
'incentive' can be an answer for 'carrot' (carrot and stick). I am not sure about the 'taken for' bit.
'one new coin setter' is the wordplay.
'one new' becomes 'in' (I've seen this in other clues).
'coin' becomes 'cent' (cent is a kind of coin).
'setter' becomes 'ive' (I can't justify this - if you can you should believe this answer much more).
'has' is the link.
Can you help me to learn more?
(Other definitions for incentive that I've seen before include "carrot" , "encouragement" , "Stimulus" , "Inducement" , "Payment to improve" .)