The Eighth Edition offers a thorough rewriting of the entire textbook, making it the most significant revision in quite a few years. As one edition rolls into the next and material gets added to or deleted from the textbook, I think many authors discover that the book keeps moving further away from what the author originally intended. There comes a time when one needs to take a step back, get reacquainted with the entire manuscript free from the pressures of having to get the next edition out the door, take stock of how all the pieces fit together in the context of an ever-evolving field, and do a thorough rethinking of how to best present the material once more as part of a cohesive whole. I experienced that feeling about 3 years ago, shortly after the last edition was published, and decided at the time to tackle the Eighth Edition as if I were writing the textbook for the first time. And that is precisely what I have done. Readers will find that although much will seem familiar, big chunks of the book have been completely rewritten and streamlined. The book still offers many detailed policy discussions and still uses the evidence reported in state-of-the-art research articles to illustrate the many applications of modern labor economics. The text continues to make frequent use of such econometric tools as fixed effects, the difference in-differences estimator, and instrumental variables—tools that play a central role in the toolkit of labor economists. And the Eighth Edition even adds to the toolkit by introducing the synthetic control method. But the text is now much leaner, making it a shorter and easier-to-read book. And it emphasizes, from the very beginning, how these empirical tools are a central part of the methodological revolution that changed labor economics in the past two decades. Empirical analysis must be much more than calculating a correlation describing the relation between two variables. It must instead reflect a well-thought-out strategy that attempts to identify the direct consequences of the many shocks that continually hit the labor market.