The surprisingly low border effect of the BigMac

The Economist's BigMac Index is widely used as an indicator of purchasing power parity. I have never been convinced that it is an appropriate indicator, though. But studies keep using it, and teachers keep mentioning it.

The latest is Anthony Landry who uses it to study the border effect, i.e., how a border adds to the cost of transportation. That assumes that BicMacs are all produced in one location and then shipped to all stores worldwide. This clearly is not the case, both for the raw material and for the assembly. While the raw material is produced centrally in each country, it is only rarely passing a border due to regulation and preferences for local product. I thus do not see the point of estimating borders effects with BigMacs.