Although it is now over three decades old, it would be hard to overstate the importance of this book to scholarship regarding the role of labor unions in the U.S. Utilizing sophisticated analytical techniques, the authors rigorously asses the costs and benefits of labor unions. They conclude that they have a net positive social benefit. All academic research on the role of labor unions since the publication of this book has had to take its methods and conclusions seriously. It is an essential starting point for serious research on labor unions in the U.S.