Sure thing.
1) The theory is laid out in Inderst/Valletti and Inderst/Dobson but I frankly don’t have an opinion on that (nor am I talking about Costco specifically). What I’m saying is based on four years of conversations with at least two major wholesalers that supply independent grocers and truly countless numbers of those grocers who shared with me the comments they heard from those suppliers.
2) The legal difference is that the first is a 2(a) violation of RPA and the second is a 2(f) violation.
3) Someone might see that response and say “but we were talking about efficiency” - and that’s my point. I’m not talking about “efficiency” - because the law is not about an economic concept. It’s about a moral concept — fairness. It’s about providing a level playing field for the small grocer serving rural America (or urban America for that matter). We don’t have a minimum wage because it’s “efficient.” We don’t have workplace safety laws because they’re “efficient.” We have them because they are moral and fair, and the same applies to Robinson-Patman. And that’s Congress’s decision to define what “fair” is — not mine.
Two questions: 1) What is your evidence for the claim that when a supplier offers Costco a lower price on a high volume order, that causes the supplier to raise prices on smaller retailers making lower volume orders?