My understanding is that essentially all of the risk of cosleeping comes from parents who are one or more of morbidly obese, alcoholic or drug abusers. Got sources that say otherwise?
Here's one (small) study that says cosleeping is safer that an separate room:
Here's one (small) study that says cosleeping is safer that an separate room:
https://onlinelibrary.wiley.com/doi/10.1111/j.1440-1754.2007...