counterfactual vs ersatz

counterfactual

noun
  • A claim, hypothesis, or other belief that is contrary to the facts. 

  • A conditional statement in which the conditional clause is false. 

  • A hypothetical state of the world, used to assess the impact of an action. 

adj
  • Contrary to known or agreed facts; untrue. 

  • Of or in comparison to a hypothetical state of the world. 

ersatz

noun
  • Something made in imitation; an effigy or substitute. 

adj
  • Made in imitation; artificial, especially of a poor quality. 

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