both omb director mulvaney and naomi ross have questioned some of the legitimacy of the obama administration's assumptions. perhaps undervaluing cost and overestimating benefits. so i'm wondering, is it there just a standard way, isn't there a standard way of evaluating cost and benefits? for how much flexibility is there? how much front can we put in cost-benefit analysis?. >> i mean, cost-benefit analysis is not some golden path to the truth. is a way of clarifying assumptions and clarifying thinking that really serves very vital accountability purpose, but assumptions can be made differently, and a lot of what we are seeing in some of the very high profile rules is the trump administration will make very different assumptions than the obama administration did. an example i know is the clean power plan. the question there is on one hand, should we count just benefits to the u.s. citizens or benefits throughout the world? traditionally, we have just looked at benefits to u.s. citizens. the obama administration counted them globally. trump administration will not. similarly, do we count code b