Zook received a B.A. in mathematics and economics from Williams College, a M.Phil. in economics from Exeter College, Oxford University, and a M.A. and Ph.D from Harvard University.

Zook is an author of books and articles on business strategy, growth, and the importance of leadership economics, including the Profit from the Core trilogy. In 2001, he published Profit from the Core, which found that nine out of ten companies that had sustained profitable growth for a decade had focused on their core businesses, rather than diversification. The sequel, Beyond the Core, examines how companies that have fully exploited their core businesses can systematically and successfully expand beyond into related, or adjacent areas. Unstoppable completes the series and examines what to do when a previously viable growth formula of the past begins to approach its limits, and how companies can change their strategic focus and redefine their core. In 2010, Harvard Business School press published an updated version of Profit From the Core, subtitled "A Return to Growth in Turbulent Times." The updated edition describes how principles from the trilogy enabled companies to continue growing during the global financial crisis that began in 2008.

All three books are based on a growth study, begun in 1990 at Bain & Company, that involves thousands of companies worldwide. The study's findings have been expanded each year.