incentive vs operative

incentive

adj
  • Inciting; encouraging or moving; rousing to action; stimulating. 

  • Serving to kindle or set on fire. 

noun
  • Something that motivates, rouses, or encourages. 

  • A bonus or reward, often monetary, to work harder. 

operative

adj
  • Effectual or important. 

  • Functional, in working order. 

  • Having the power of acting; hence, exerting force, physical or moral; active in the production of effects. 

  • Producing the appropriate or designed effect; efficacious. 

  • Based upon, or consisting of, a surgical operation or operations. 

noun
  • An employee or other worker with some particular function or skill. 

  • A spy, secret agent, or detective. 

  • A participant in an operation. 

How often have the words incentive and operative occurred in a corpus of books? (source: Google Ngram Viewer )