Fair to whom? To people raising a child? They already know how much it costs. To people considering raising a child? I don't think it's unfair to make a few people stop and say "Whoa, I can't afford that", because the point of the fact is that a lot of people have children who really can't afford them.
It would, in fact, be less fair to underestimate the cost of raising a child than to overestimate it. It's less fair to the potential parents, and less fair to the potential children.
And, finally, it doesn't matter if it's fair, because life isn't actually all that fair, and that's one of the more important lessons a parent can teach a child. Which brings me back to questioning where you have any expertise, any authority, or any grounding whatsoever to question a paper published on a) economics, which you clearly don't grasp from previous posts, and b) parenting, which you have also just proven yourself not to grasp.
I also question whether you stop and read the posts that you spew, the completely illogical and improbable 'solutions' that you place in this forum every time you open your browser, but that's not particularly a conversation for this forum. Or ever, since come to think of it, I don't want to have it.