I tried to look at that time the exact reasons why it was rejected, not just the lazy "it was the jews" explanation,apparently it used to small samples for the other test subjects (books games, etc) and it lacked consistent results when tested. So while the results in average were in favor of piracy, the margin of error was too big to set it on stone.
Most of the study is supposed to reveal a sampling effect, basically if you keep coming back to a pirated something it is more likely you or someone who sees you using it, buys the original product.
Since movies are more of a one time thing only, the few published parts of the study reveal they actually had losses.
But in the case of games i think this effect will be stronger BUT only if the games is popular enough, while small games will most likely have losses since they can't benefit from a big word of mouth or showcasing to the public.
I ve seen developers posting these " if you like it please consider it buying" messages in torrent websites, their company falling months later, it's a sad thing to behold.