The forces that are driving the nation’s top technology talent to just a handful of cities have intensified in recent years, leaving much of the nation behind as the U.S. becomes a more digital economy, according to a new study.

Just five metropolitan areas—Boston; San Diego; San Francisco; Seattle; and San Jose, Calif.—accounted for 90% of all U.S. high-tech job growth between 2005 to 2017, according to the research by think-tank scholars Mark Muro and Jacob Whiton of the Brookings Institution and Rob Atkinson of the Information...