What is the Flake Equation

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I’ve been going through the XKCD website and stumbled upon this one. The Flake Equation. A pastiche of the famous Drake Equation.

Instead of trying to find life, this one tries to discover how many people have had seen an Alien or UFO.

Change the figures below and click “Update” to see what the new result is. The only one that you can’t update is the population of the World that has been taken from a source on the Internet.
P =

W_P: World population*
C_R: Fraction of people who imagine an alien encounter because they’re crazy or want to feel special	One in
M_I: Fraction of people who misinterpret a physical or physiological experience as an alien sighting	One in
T_K: Probability that they’ll tell someone	One in
F_O: Average number of people they tell
F_I: Average number of people each friend tells this “firsthand” account
D_T: Probability that any details not fitting the narrative will be revised or forgotten in retelling	in
A_U: Fraction of people with the means and motivation to share the story with a wider audience (blogs, forums, reporters)	One in