When you should play lottery?

Nowadays, lottery is quite a popular game in many places. A lot of people were infatuated to this game and in the hope of become millionaire by $1. Now, let’s view playing lottery as a business and evaluate it in economic way of thinking.

Take MEGA million as an Example:

(Up to I post, the jackpot has reached $88,000,000)
Cost: $1

Revenue: 88,000,000 / 175,711,536 + 250,000 / 3,904,701 + 10,000 / 689,065 + 150 / 13,781 + 7 / 306 + 10 / 844 + 3 / 141 + 2 / 75 = 0.5008 + 0.0640 + 0.0145 + 0.0109 + 0.0227 + 0.0118 + 0.0213 + 0.0267 = $0.6727

Net income = $0.6727 – $1 = $-0.3273

Based on this amount of the Jackpot, the net income is negative. To an economist, this lottery is a bad business which will cause the loss of money. So compared with lottery, an economist would rather like to steal cars. But, you may notice that in the equation of revenue, there is a variable which can affect the amount of revenues and net income: that is Jackpot. So it is possible for the net income become positive.

If the net income >= $0:
Revenue = net income + cost = $0 + $1 = $1 = Jackpot / 175,711,536 + 0.1719
Jackpot = $145,506,723

So when the amount of Jackpot is more than $145,506,723, the net income will be positive, which means that lottery will become a profitable business and you can join it.

Further thinking:
However, even when the net benefit is negative, there are still thousands of thousands people play this game. Do each one of them has none economic knowledge? Definitely, yes, some of them have. But why they still would like to “waste” their money in this losing money game? If the economic consideration is not the only reason that affect a customer to make a decision, what else?

I think the psychology of the customer should be the answer. Because these one dollars give them the hopes of becoming millionaires out of “nothing”, although the chance of it is really, really small. After all, better than no hope!

Should there be some thing else?