European tax-based changes more than sufficient to encourage antisocial behaviour (3,1,3,7)
I believe the answer is:
set a bad example
'encourage antisocial behaviour' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'european tax-based changes more than sufficient' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'changes' indicates an anagram.
'more than sufficient' becomes 'ample' (I've seen this before).
'e'+'tax'+'based'='etaxbased'
'etaxbased' anagrammed gives 'setabadex'.
'setabadex'+'ample'='SET A BAD EXAMPLE'
'to' is the link.
Can you help me to learn more?
(Other definitions for set a bad example that I've seen before include "Give harmful lead (to others)" , "wasn't a good model" , "Be a poor role model" , "Be a harmful influence" .)