advisability vs expediency

advisability

noun
  • The quality of being advisable or prudent. 

  • An instance of advisability; a consideration in determining overall advisability. 

expediency

noun
  • The quality of being fit or suitable to effect some desired end or the purpose intended; suitability for particular circumstance or situation. 

  • An expedient. 

  • Pursuit of the course of action that brings the desired effect even if it is unjust or unprincipled. 

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