How in the world would anyone come up with "the opposite conclusion."? Are you suggesting that the Senate plan (S2611) would result in fewer immigrants?
If you do this I do not believe you will honestly accept the claim that another 100 millions will come here. Not even in 20 years.
I have read it and find it entirely credible. What assumptions do you not find valid and what do you think the result will be? 80 Million? Any which way, I think the answer is too many!
An "opposite" conclusion would be one which instead of finding a huge impact finds No impact or a small one. Such a study would be gone over with a fine tooth comb and any flaw in methodology or fact revealed. You did not do that kind of analysis for this one which is a form of intellectual dishonesty.
In fact, it is precisely the studies which you believe or want to believe which should be MORE closely scrutinized.
In the last twenty years apparently 11-12 million Illegals have arrived hence I see no reason to assume the next twenty years will be different.