The MIT Libraries has subscriptions with several major analysts covering a broad range of industries, including Gartner, Frost & Sullivan, Forrester, IBISWorld and more. These are highly respected, highly citable reports that people in the industry pay thousands of dollars a pop for. If you are an enrolled student and need to do market sizing, you should definitely leverage this amazing resource while you can - your access will end when you graduate.
To use this wonderful resource, visit https://libguides.mit.edu/innovation.
This is a landing page that MIT librarian Nicholas Albaugh put together for students interested in doing market research on innovation and entrepreneurship. This landing page includes links to many hugely valuable analyst portals for which MIT has a site-wide subscription. Example analysts include: Gartner, IBISWorld, Marketline, Forrester and teh like. You can literally pull down hundreds of thousands of dollars' worth of analyst reports in an hour from these resources.
Please respect the policies that make this resource available to you. Here is the MIT use policy as of September, 2018.
"The Massachusetts Institute of Technology is an independent, private university. Institute facilities, including the Libraries, have the primary purpose of supporting MIT’s educational and research programs. The MIT Libraries may also serve the local community, the nation, and the world through the use of Libraries facilities, particularly when there is a compelling need or interest that can be met without detriment to the Institute’s primary purpose.
Access to and use of the MIT Libraries is a privilege extended to the members of the MIT community of faculty, students, and staff; including members of their immediate families and sponsored affiliates. Access to MIT Libraries’ facilities, services, and resources by visitors is limited to meeting a specific need for the scholarly, research, or educational materials and services available in the MIT Libraries."
Analyst reports from these portals should never be forwarded or shared with people outside the above description.