Interesting, one out of four is not actually making anything.

The following statement is attributed to Kara Calvert, Director of the Drone Manufacturers Alliance:

Leading global drone manufacturers 3DR, DJI, GoPro and Parrot today are forming the Drone Manufacturers Alliance, a coalition that will serve as the voice for drone manufacturers and our customers across civilian, governmental, recreational, commercial, nonprofit and public safety applications. We will advocate for policies that promote innovation and safety, and create a practical and responsible regulatory framework.

There are significant economic and social benefits to drone operations in the U.S., and industry must work with policymakers to ensure a safe environment for flying. The Drone Manufacturers Alliance believes a carefully balanced regulatory framework requires input from all stakeholders and must recognize the value and necessity of continued technological innovation. By highlighting innovation and emphasizing education, we intend to work with policymakers to ensure drones continue to be safely integrated into the national airspace.

http://dronemanufacturersalliance.org/