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 exam

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.