Government sponsored lotteries operate around the world. Their popularity has grown substantially over time. Legal lottery gambling generates significant public revenue, much of it from the lower part of the income distribution. Lottery is almost always an unfair bet, so explaining the purchase of lottery tickets by risk-averse consumers has long challenged economic theory. Lotteries can be analyzed from the perspective of public finance, as source of public revenue, or consumer theory, as a consumer commodity. We survey the state of economic research on lotteries from both perspectives, focusing on the key empirical findings.