How else would you explain why people play the lottery? It's well-known that the expected value of any given ticket is negative (except in rare cases), unless you place some entertainment/fantasy value on playing.

The expected value of insurance is also negative (it has to be, or else insurance companies wouldn't be able to pay their expenses), but people buy it for the same reason: the rare payoff is life-altering, while the much more common cost doesn't make much difference in comparison.

Why would you think lottery players are using your "expected value" model to decide whether to buy tickets?

If I believe "I'm lucky" the expected value is positive.

I mean, this is why I chuck 5 bucks in every once in a while. I know, realistically, I am not going to win, but the fantasy is a fun activity. The human brain is weird.

That's much more rational than buying lottery tickets because you are in desperate need of money.

That seems accurate.

It’s true. If I won the (big) lotto I would no longer enjoy buying lottery tickets.

Isn't that the point of playing the lotto?