Sorry, but you are plain wrong, and those researches show that.
I agree, that's wishful thinking.
But there is some wishful thinking by the publishers as well.
Truth is, people who pirate games do so because they can pirate them. They don't buy games, they just pirate.
It's not like they would buy all these games if they couldn't pirate them. You really believe someone who downloaded the whole Re-Dump scene of PS2 games or something would buy them if they didn't have that chance? And yet, each one of the publishers of all those 2.000+ games would claim they lost a sale. Each and every single one of them.
That's the biggest myth about piracy. Publishers want you to believe that 1 pirated copy = 1 lost sale but that's pure science fiction. Only a tiny minority of pirates would buy games they can't pirate.
People who buy games buy them. People who pirate, pirate. That's it. The only thing DRM does is making the life of the buying customers harder.