3 psychological reasons why we buy lottery tickets when there's virtually no chance of winning

The Powerball jackpot prize has hit a record high of $1.5 billion - and the prospect of taking most of it home is tantalizing even for the least money-minded among us.

Unfortunately, your chances of winning are only about 1 in 292,000,000. In fact, it says just that on the Powerball website.

So why are millions of people rushing to buy tickets before Wednesday night's drawing?

We spoke to Robert Williams, a professor of health sciences and gambling studies at the University of Lethbridge in Alberta, who outlined three fascinating psychological phenomena that explain this irrational behavior.

We're not trying to dissuade you from entering the lottery, by the way. But the ideas below will help you understand why you - and most everyone else - are inclined to participate.

1. We fall prey to the "near miss" effect.

The "near miss" effect describes what happens when you feel like you almost won and want to try again - even though you weren't even close.

Williams explained how the near-miss effect plays out in the Powerball. As mentioned above, your odds of getting all six numbers right are about 1 in 292 million.

So what are your odds of getting three out of six numbers right? You might be tempted to divide the original number in half and say 1 in 146 million.

But you'd be wrong. They're actually about 1 in 600. (Although even if you got three out of six numbers right, you'd only win $7.)

The problem is that when people get half the numbers right, they think they were "so close!!!" and promptly reenter the lottery. So while they might believe that they just missed the target, the difference in probability is actually in the hundreds of millions.

2. Our brains haven't evolved to understand such low probabilities.

"We evolved to have some appreciation of numbers," Williams said. For example, we can easily comprehend the difference between an army of 10 soldiers versus an army of 100 or 1,000.

Numbers beyond that, however, were never relevant throughout most of human history, Williams said. Who needed to count the millions of stars in the sky or blades of grass in a field?

That's why odds of 1 in 292 million don't sound terribly different from odds of, say, 1 in 100,000 - at least not until you stop to think carefully about it.

Certainly, the fact that your odds of winning the Powerball jackpot prize recently went from 1 in 175 million (when you had to select six numbers between 1 and 59) to 1 in 292 million has little impact on people's willingness to participate in the lottery.

3. The lottery plays into our "availability bias."

The "availability bias" is the term for when we overestimate an event's likelihood based on how strong our memories of that event are.

So when we try to figure out our odds of winning the Powerball jackpot prize, Williams said we think about the few people we've heard about who won the lottery - instead of the millions of people who didn't win.

That's because jackpot winners always make the news, and jackpot losers never do, so the stories of the winners stand out much more in our memories.

"It makes [winning] seem possible," Williams said.

So should you buy a ticket?

That's up to you.

Williams, for one, said he doesn't necessarily want people to stop playing lotteries. There are much more serious forms of gambling, and the harm that comes from playing the lottery (losing $2) is relatively minor.

Yet Williams said it's useful to know that playing the lottery is merely a cheap form of entertainment - you spend $2 for the chance to fantasize about becoming a millionaire. As long as you know there's "no realistic chance of winning," he said, it's generally fine to play.

Perhaps the biggest problem with modern lotteries, Williams said, is how they portray the effects of winning.

"They deceptively convey the notion that life will improve," he said, when in fact, "we adapt to our material gains."

In other words, while you might be happy for the first few months after you hit the jackpot, eventually that elation will wear off and you'll have new concerns, like the stock market.

As billionaire Mark Cuban told Business Insider: "If you weren't happy yesterday, you won't be happy tomorrow. It's money. It's not happiness."