Olson v. United States , 292 U.S. 246, 255 (1934); see Section 4.3. This may be true of not only the buyer’s but also the seller’s motivations (e.g., sellers may claim such sales as a tax write-off). Cf. United States v. Leavell & Ponder, Inc., 286 F.2d 398, 405-06 (5th Cir. 1961).