The drawing of lots for property, slaves and other prizes has a long record in human history, including many instances recorded in the Bible. Lotteries are an established part of state gambling laws and a common way to raise money for public purposes. They have been used for a variety of projects, from subsidized housing units to kindergarten placements. But critics say the lottery is addictive, promotes irrational behavior and amounts to a regressive tax on lower-income people. And they point to a fundamental conflict between the lottery’s desire for revenue and its duty to protect the public welfare.

The states that established their lotteries in the immediate post-World War II period saw them as a way to finance a broader array of services without burdening middle-class and working people with especially onerous taxes. They were right that lotteries can raise significant revenues. But they were wrong to assume that this extra revenue could solve all of their problems.

Most lotteries operate along the same lines: A state legislates a monopoly for itself; establishes an agency or public corporation to run it (as opposed to licensing private firms in return for a share of the profits); begins operations with a modest number of relatively simple games; and then, as pressure for additional revenues increases, progressively expands the offerings and complexity of the lottery, particularly by adding new games. A lottery’s prize pool consists of the total value of tickets sold, minus expenses such as promotion and taxes.