The Illustrated Guide to Criminal Law
Chapter 4: Deterrence 
Page 7: Perception is everything

NARRATOR

For both specific and general deterrence, the AMOUNT of punishment matters surprisingly little.

Average Joe talking head

AVERAGE JOE

After all, how many people even KNOW how much time any particular person got for any particular crime?

Apart from criminal lawyers and experienced offenders, almost NOBODY has any idea how much punishment they’re actually facing—if any.

NARRATOR

What matters most instead is the threat that SOME punishment will be imposed…

…in other words, it is the PERCEPTION that one is likely to be punished (if caught) that is the deterrent.