Lots of people are getting hung up on the measurement.
The key word is "imagine" y'know.
Imagine that the Imagination Quotient is a number between 0 and 1, with 0 being the inability to imagine even what you're looking at, and 1 representing the ability to imagine a real thing unseen in full detail. The Imagination Quotient required to imagine that someone's utility is 80 is would be an proper imaginary number.
I can't even imagine the Imagination Quotient required for some social scores.