Before revision:  We show that the original choice of Muhammad Yunus, of a group size of five people, is, under the right ( and, we believe, reasonable ) hypotheses, either close to optimal, or even at times exactly optimal, i.e., the optimal group size is indeed five people.
After revision:  We show that the original choice of Muhammad Yunus, of a group size of five people, is, under the right , and, we believe, reasonable ) hypotheses, either close to optimal, or even at times exactly optimal, i.e., the optimal group size is indeed five people.