Vikki Velasquez is a researcher and writer who has managed, coordinated, and directed various community and nonprofit organizations. She has conducted in-depth research on social and economic issues ...

Twenty years after the introduction of the theory, we revisit what it does—and doesn’t—explain. by Clayton M. Christensen, Michael E. Raynor and Rory McDonald Please enjoy this HBR Classic. Clayton M.

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...