OK, let's try to get this discussion back to railroad (and Amtrak) industry cash flow and revenue recognition.
First, addressing the period A-Day to November 71 when Amtrak started to assume cash collection and revenue accounting, this was really a "neutral" for the railroads. On A-Day, AAR Passenger Mandatory providing that the road selling the ticket gets the collection (more likely than not "green stuff" cash). This collection was then divided between the interline carriers. Roads such as "my MILW" did have an advantage when that Chi-SF ticket was bought and subsequently was divided between the UP, SP, and Pullman Co. Post A-Day such "division" continued.
However, what our discussion overlooks, is that under the Agreement, Amtrak was going to provide to the roads an advance payable by wire on the third day of each month. That advance was an estimate of their costs, i.e. everything on A-Day, less estimate of ticket sale and Dining Car collections. Point is that Amtrak actually enhanced the roads's cash flow with "it all up front" and paying people and buying gas later in the month.
I can recall first hand how Charlie Schiffer, MILW Treasurer at that time (a "regular guy" who did not expect a Trainee Auditor to "bow and scrape" unto his feet) remarking how that advance of about $1.2M showing up by wire on Monday May 3 "made for a happy day".
So as Amtrak assumed collection of receipts (cash, credit card), so went up the advance. As Amtrak assumed activities of running the trains (on-board service, maintenance of equipment, station employees), down went the advance. When during '83 (I was gone), Amtrak assumed Train and Engine employees, the advance comprised what it roundly is today - payment for access (piddly) and performance (also piddly).
All told, I have to think, it would have been a "neutral" with cash flow for operations, excluding entry fees, had it been "Thanks....".