[zebulom]

Buying a lottery ticket is no more irrational than buying a movie ticket. It buys you a little thrill -- the possibility that you may become rich.

[dinkumthinkum]

No I don't think that works. Many people buy lottery tickets and really think they are going to win. Movie tickets to entice people with false hopes of riches. They also don't involve gambling addiction.

[Fomite]

Buying a lottery ticket is rational if the cost of the ticket is offset by the relative increase in your pleasure that comes from dreaming of winning.

For example, if you gain >$price of a Powerball ticket worth's of entertainment from musing about how you'd spend the prize, it's a rational purchase.

On the other hand, buying two tickets isn't rational. You get no extra dreaming, and your expectation of winning hasn't moved essentially at all.

[sanoli]

Not really. If you buy 10 tickets, you're buying an extra dose of thrill because you think "I bought ten, I got a better chance of winning".

[Fomite]

My assertion is true even for people who understand probability, and thus won't get much thrill about multiplying ~0 by 10.