This is the first book on welfare economics to be primarily intended for undergraduates. It explores such concepts as Pareto optimality in a market economy, the compensation criterion, and the social welfare function, and analyzes market failures using different ways of measuring welfare changes. The book covers public choice, and the issues of efficient provision of public goods, government failures, and efficient and optimal taxation, concluding with an examination of applied welfare economics, methods for revealing people's preferences, cost-benefit analysis, and project evaluation in a risky world.