Finding out if company founders are graduates for a dissertation In a nutshell, I'm thinking about doing research and analysis of founders of rapid-growing companies during the last decade or so, to see if there is an increasing trend of non-graduates successfully founding these firms, or if having a degree (especially in the same industry as the company) is highly recommended.

However, I'm afraid the sources from which I can obtain this data might not be valid in the academic environment (or in any environment). For instance, I could go and check a founder's LinkedIn profile, but:


Is LinkedIn a reliable source of data for a dissertation? I don't think so.
Many people decide not to show their entire education or job history, because it might be irrelevant or because having a degree from a university with a low reputation could be a negative thing.


Trying to contact these founders to interview them is almost impossible.

I'm not experienced in doing academic research, so my question is: is there a reliable source of data for this that I could use for my research?

This is in the UK, if it makes any difference.
The most reliable source is the college/university itself. You can compile a list of where these founders when to school, and call the school itself and ask the question. The question has to be Yes/No so you will have to phrase it like: "Did you award such-and-such degree to John Smith?" 

If that is too labor intensive, a simple Google search of the person "John Smith College" should return results from reputable sources such as Time, Business Insider, etc.