Over the last year or so I have studied and written quite a bit on the topic of timeouts. You can read all of the posts I have written (in English and in Polish) by following this link.
The upshot of all of the research I have done with Ben Raymond is that timeouts do not seem to work in the way that we (coaches, fans, administrators) like to think that they do, that is they have no impact on the game.
An American researcher, studying USA college matches and looking at over 5,000 timeouts found eerily similar results. They are summarised in the infogram below.