The Ceteris Paribus Fairy

This is how I think about the concept of ceteris paribus in economic thought.  It’s a nice way to make things work out swimmingly, but reality often paints a different picture.  Fairies are a convenient mascot for something like this.

Sometimes the Latin translation varies depending on the source, but the meaning is the same.

The first econ professor I ever had referred to ceteris paribus as “KET-err-iss”, and I can’t seem to quit pronouncing it like that, even though it’s not the correct Latin pronunciation.

 It’s not bippity boppity boo or anything that amazing, but still.

Ceteris Paribus Fairy doesn’t care about sexiness.  Might he need a shave and a gym membership?  Perhaps.  But who are we to judge?

Again, he’s not turning teeth into money or anything that amazing.  
But it’s still an important power to wield, at least in economics.

Really, he is.

Without the magical presence of the Ceteris Paribus Fairy, Hootie is not a good dog when he goes on walks.  
In fact, most of the time, he is a complete spaz on walks.  

That's because without the Ceteris Paribus Fairy around to hold all other variables constant, Hootie (the well-meaning dog that he is) is easily distracted.  And my chances of being dragged along as he chases a squirrel up a tree are increased.  By a lot.  

In essence, the Ceteris Paribus Fairy allows us to make predictions with confidence about Hootie’s behavior during a walk, regardless of the environment or circumstances. 

"What gives?" you might say.  Why even bother with the Ceteris Paribus Fairy when he never seems to be around in real life?  


Well, the answer is because he's an essential part of basic economic theory.  And if you, a hapless student of economics, refuse to believe in the existence of the Ceteris Paribus Fairy, you'll doubtlessly end up thinking too much about what else could happen in the situation at hand.  It's a flaw most smart, logically-thinking people fall into.  On economics exams, it often results in wrong answers and bad exam grades.  


So go ahead.  Take advantage of the Ceteris Paribus Fairy.  In fact, he wants you to.  Really.  And your grades might just thank you for it.  

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