Peers interfere improperly in economic system (4,10)
I believe the answer is:
free enterprise
'economic system' is the definition.
(free enterprise is a kind of economic system)
'peers interfere improperly' is the wordplay.
'improperly' is an anagram indicator (I've seen this in other clues).
'peers'+'interfere'='peersinterfere'
'peersinterfere' is an anagram of 'FREE-ENTERPRISE'.
'in' is the link.
(Other definitions for free enterprise that I've seen before include "capitalist system" , "Economic system" .)