Is there any case law where a plaintiff is required to make a restitution claim for lost income as a result of speculation or speculation?

To be sure, a restitution award, whether for lost income or otherwise, cannot be based on mere speculation. See United States v. Cienfuegos, 462 F.3d at 1168; see also S. Rep. No. 104-179, at 19, reprinted in 1996 U.S.C.C.A.N. at 932 (stating committee view that mandatory restitution should not apply where "losses are speculative" or "not clearly causally linked to the offense"). No such concern arises in this case because the district court conservatively calculated lost future income by reference to Pistone's modest recent taxable earnings, and Messina did not, and does not now, object to that calculation.