handset manufacturers in U.S.A, Europe, and Japan. We choose the "event study" methodology to evaluate the impact of iPhone … carriers and the handset manufactures in U.S.A, Europe and Japan?" The results show that the impacts of iPhone present … results of financial profits show that almost of all telecommunications carriers in U.S.A and Japan grow their profits after …

) productivity growth, as more productive businesses displace less productive ones. However, this research has been limited by the … productivity measures. If prices reflect idiosyncratic demand or market power shifts, high "productivity" businesses may not be … selection and productivity growth using data from industries where we observe producer-level quantities and prices separately …