> doesn't prevent drug companies from allocating volume on a country-by-country level and maintaining price discrimination.
It does; for price discrimination, there are three criteria that all need to be satisfied, and one of them is the ability to restrict resale between market segments. If market segments are free to trade with each other, the supplier cannot price-discriminate.
> This happened back 6-7 years ago when getting your script filled by a Canadian pharmacy was all the rage. The drug companies simply setup quotas for Canada. They have a good estimate of how much drug Canadians need. If a wholesaler tries to buy more, the drug company tells them no. Then all of a sudden Canadian wholesalers are in a bind. Do they sell to Americans and tell the Canadians no?
It's important to understand the difference between the short-term impact and the long-term (steady-state) impact. The case you're referencing is an amusing one, because it's actually AstraZeneca's proactive campaign against what was then a touchstone of the healthcare reform bills[0]. At the time, unrestricted trade in pharmaceuticals was not possible between the US and Canada, and AstraZeneca was making a threat to try and kill the provisions that would have permitted it[1].
The only reason that they can set these quotas in the first place is that US wholesalers can't (freely) export to Canada, and vice versa. If the ban on that had been lifted, AstraZeneca wouldn't be able to set quotas per-country in the first place. They could try, and succeed in the short-term, but in the long term, the prices in both markets would be forced to converge (with the difference bounded by the costs of import/export).
[0] Remember the date: April 2009, just a few months into Obama's inauguration. The public option was still theoretically on the table, and the Baucus plan hadn't happened yet.
[1] It worked - that was one of the parts of the ACA that was killed before it got a vote.