A staker’s risk adjusted return stake increases with the amount of stake they have or the larger the pool they become a part of. This article provides a framework for understanding why that is the case. The difference in return between a solo validator, an individual or entity running their own, single validator, and large pools is called the cost of altruism.

See paper (here) which is a small part of a much larger project. I also gave a presentation on this topic to the EF, see here