Spectrum licensed to U.S. wireless carriers generates more than $400 billion annually in economic activity, according to a report issued by the Brattle Group and prepared for CTIA. The $400 billion figure includes direct and indirect economic impact generated by the mobile carriers, but excludes billions more in economic benefits produced by mobile health, mobile education, the app economy and other sectors that use licensed spectrum as a platform for their own business models, according to the repor.