Lotteries are one of the oldest forms of public finance, a way to distribute goods and property by drawing lots. They were popular in ancient Rome-Nero was a big fan-and are referenced throughout the Bible, from choosing kings to distributing slaves and land. Lotteries also played a major role in American history, financing projects including the construction of Harvard and other colleges and providing money to the Continental Army during the Revolutionary War. Today, they are still used by state governments to raise funds for everything from constructing roads to funding public universities. But lotteries are also controversial, raising concerns about compulsive gambling and the regressive effect on lower-income groups.

For these reasons, lottery advocates have begun to reframe the debate. Instead of arguing that a lottery would float a state’s entire budget, they are now pitching a specific line item, usually education, elder care or aid for veterans. This approach makes it easier to explain why a lottery should be legalized, since voters can see how their vote would help them support a particular government service they value.

But the larger issue remains: How to control state gambling and ensure that proceeds are primarily for public benefit. This is especially challenging in the case of the lottery, where revenue growth tends to be explosive initially and then levels off, requiring constant innovation and a large investment in advertising. As a result, lottery revenues rarely reach the level that enables states to meet their other spending obligations.

A key issue here is that the lion’s share of lottery revenue goes toward prizes, not state coffers. This makes it difficult to control the size of prizes and ensure that proceeds are distributed based on need, not profit. The best way to address this is by ensuring that the lottery’s randomness is independently verified. To do this, we can use the same statistical analysis that is employed to validate random number generators in computer software. For example, we can plot the distribution of winning numbers from the last ten years and show that the winning combinations appear with relative frequency. If the distribution is not close to a straight line, then we have reason to doubt the lottery’s randomness.

But the biggest problem of all is that lottery profits are not transparent, a fact that helps fuel public mistrust. Consumers are not clear about the implicit tax rate on their ticket purchases and thus can’t assess whether they’re paying a fair price for a chance to win. The fact that many of the same games are offered in both state and private lotteries exacerbates this confusion. To counter it, we need to rethink the structure of lotteries and the way they are promoted. This would allow us to focus on promoting games that are truly fair and beneficial to the public. We can start by establishing some basic rules. For example, we should not promote “instant” games that require a player to purchase multiple tickets in order to have the chance of winning a prize.