Argentina's response to this is fascinating and fiendishly clever.
Walk into any McDonald's in Buenos Aires and look up at the big lighted menu board and you will find the usual stuff: Cuarto and Angus Tasty and McPollo and McNifica and all the rest. Look again, a little more closely, and you'll notice there is no Big Mac. No Big Mac at McDonald's? Huh?
Why isn't the Big Mac advertised on the menu? The rumor is that the Argentine government has asked (perhaps even paid?) McDonald's to keep the price of that particular item artificially low because of the inflation index. McDonald's has complied with the request but, to avoid losing money selling an item below cost, has taken the Big Mac off the published menu to discourage customers from ordering it.
We temporarily suspended our aversion to McDonald's to test this out. We walked up to Palermo to enjoy the Thays Botanical Garden; it was lunchtime and we were getting hungry, so we stopped in a McDonald's on Las Heras near the park. All the listed combo meals (sandwich, fries, and drink) ranged from A$32 to A$42 (US$7.75 to US$10). There was no Big Mac on the menu board but we asked, and sure enough they had it, at A$21.90 (US$5.25), a half to a third off the price of any other meal. We also discovered that ordering a Big Mac ensures that you get a freshly prepared burger, since they don't make them in advance and stick them under a heat lamp.
The other big surprise was that the Big Mac was -- dare I say it? -- tasty. Burgers are hard to come by in Buenos Aires, and the Big Mac meal made a pretty good, and pretty cheap, lunch.