Historically, lotteries have been popular fundraising instruments in Europe. They are relatively easy to organize and widely acceptable as a painless form of taxation, a reputation reflected in the name lottery itself: the English word derives from the Dutch noun lot meaning fate or chance. Lotteries were originally used to raise money for poor people, and later for a wide variety of public usages such as canals, roads, libraries, churches, colleges, schools, hospitals, and other infrastructure.

Today, the main function of a lottery is to offer money prizes in return for a purchase of a ticket, or tickets. Prizes are normally advertised as a lump sum, although in some countries (mainly the United States) winnings can be paid out in an annuity. Costs of organizing and promoting the lottery, and profit to organizers or sponsors, are usually deducted from the total pool.

In the United States, people spend more than $100 billion a year on lottery tickets. It’s the largest form of gambling in the country, and there’s a good reason for that: Lotteries are a big source of revenue for state governments.

But, there’s a darker side to lottery playing that’s often overlooked. For many, particularly those in the lowest socioeconomic groups, it provides a small, irrational hope that they will win — even though they know their odds are bad. In other words, they’re buying a little bit of happiness. And that’s something that deserves a closer look.