Making more sense with numbers, part 4
I'll leave the psychological arguments to others; the point is that thinking carefully isn't always as easy as it seems. If you're not convinced, read the start of that article down to "Before I tell you the answer, I have a request," and then write down your answer before proceeding. Then try out the online version to see if you got the right answer, to get a visceral feel for the game, and to see the reasoning.
Once you get the hang of those, try out Monty Hall’s Other Problems.
Do you now think you've got the hang of it? Just to confuse things a bit more, read Behind Monty Hall's Doors: Puzzle, Debate and Answer?, Tierney's 1991 report of playing the game with Monty Hall. By the end, you may have an even deeper appreciation of the challenge of making sense with numbers.
And if you wonder what this might have to do with business, remember that the impetus for Tierney's column was Yale economist M. Keith Chen's application of the Monty Hall problem to psychology. Are similar gotcha's waiting for us in business?
PS: Yes, there is a Making more sense with numbers, part 3.