by-product vs consequence

by-product

noun
  • A side effect. 

  • A secondary product; something made incidentally during the production of something else. 

consequence

noun
  • Chain of causes and effects; consecution. 

  • That which follows something on which it depends; that which is produced by a cause. 

  • A proposition collected from the agreement of other previous propositions; any conclusion which results from reason or argument; inference. 

  • Importance with respect to what comes after. 

  • The power to influence or produce an effect. 

  • Importance, value, or influence. 

  • A result of actions, especially if such a result is unwanted or unpleasant. 

verb
  • To threaten or punish (a child, etc.) with specific consequences for misbehaviour. 

How often have the words by-product and consequence occurred in a corpus of books? (source: Google Ngram Viewer )