A lottery is a contest in which tokens are distributed or sold and winners are chosen at random. The resulting prize may be cash or goods, but it is also common for lotteries to distribute services such as housing units or kindergarten placements. Some states have even organized a lottery for sports draft picks.

The reason people buy tickets for these events isn’t just the inextricable human impulse to gamble, although it certainly plays a role. Lottery promotions are often designed to make you think you’re doing your civic duty or helping children when you purchase a ticket, and these messages resonate well with people in an era of limited social mobility.

But that doesn’t mean the lottery is inherently good. It has some serious drawbacks, especially for low-income people who don’t have other ways to improve their lives. And that’s why a new study on the lottery deserves your attention.

In this article, the authors explore the underlying mathematical dynamics that drive lottery purchases. They find that the most important factor is a person’s perception of how much she could gain if she won. People who believe they would gain the most if they won buy the fewest tickets, as do people who perceive that their chances of winning are relatively low.

They also find that people who purchase tickets in bulk, buying thousands of them at a time, tend to be more successful in winning the lottery than those who buy fewer tickets. This suggests that decision models based on expected value maximization fail to explain the purchases of many lottery players.