[lojack]

> I've done the math on my local lotteries and I only buy tickets when the EV of the return is greater than the cost of a single ticket.

If you want to get really technical, you also need to consider the number of people playing. When the jackpot gets extra high more people tend to play, so the likelihood of having to split a jackpot (which happens all the time) becomes higher. Without doing the math I would guess EV of the return is rarely ever greater than the cost of a single ticket.

[MaximumYComb]

I factored that in when I did that calculations. How often are their multiple winners and when there are multiple, how many. A surprising amount of the return comes from the non-jackpot prizes, 58% or something. You'll see crowds lining up to buy tickets and yet no winner for a few weeks.