Alas, I have no citations, but I have heard on the grapevine, as it were, that there are multiple studies showing that glove-less boxing is safer than boxing with the normal gloves.

This makes a lot of sense because, as I said in another comment this this article, bareknuckle completely changes the gameplan. The hand is very easy to break and the gloves do a great job at protecting them. When you don't have gloves you can't just go throwing haymakers since it's very likely you're going break your hands doing it. Heck, even "defending with your forehead" becomes a viable strategy against a gloveless opponent. I bet in these scenarios the fighters get exposed to much weaker shots in average. The goal here is to land that one precise punch right in the off switch.