Devious racketeer harms pollster's task (6,8)
I believe the answer is:
market research
'pollster's task' is the definition.
The definition suggests a singular noun which matches the answer.
'devious racketeer harms' is the wordplay.
'devious' is an anagram indicator.
'racketeer'+'harms'='racketeerharms'
'racketeerharms' with letters rearranged gives 'MARKET RESEARCH'.
Can you help me to learn more?
(Other definitions for market research that I've seen before include "test of customers' requirements" , "Study of consumers' needs and preference" , "Consumer studies" , "study of consumer needs" , "retail study" .)