Is Epistocracy better than Democracy?

According to Georgetown University political philosopher Jason Brennan, we’d be better off if we replaced democracy with a form of government known as “epistocracy.”

Epistocracy is a system in which the votes of people who can prove their political knowledge count more than the votes of people who can’t. In other words, it’s a system that privileges the most politically informed citizens. 

But here come two vital questions with this theory- who is to considered as politically informed citizen and who will decide the criteria ? 

 Epistocracy: a political theorist’s case for letting only the informed vote