Is there another food item that is so ubiquitous? Some cultures don't eat rice. Some cultures don't eat potatoes. Some cultures don't eat corn. Some don't eat tofu. And for the many food items that are somewhat easy to find worldwide, demand will be different.

And is there another measuring stick that would give us the simultaneous jab against globalization and corporate imperialism?

When I traveled a bit last year, it seemed KFC was everywhere! I would think a Chicken Index would be as good as any to have.

KFC is definitely more popular than McDonalds in Asia. Chicken and pork are much more popular than beef. I've always assumed it had to do with the stupendously inefficient nature of beef in terms of cost & land.

I went to KFC the other day, since the McDonald's next door was way too busy. KFC doesn't always do better than McDs, at least in Beijing.

Beef is also taboo in India.

McPaneer sandwich index?

It's not common in Brazil.

Not really food, but ubiquitous and immune to local shocks: insulin.

Not true. My dad's side of the family lives in Libya and one of my aunts requires insulin- the price went up at least 5x during the worst of it and it's still currently 3x of what it used to be.

I mean differential shocks -- you want the index/item to track the general price differences between the countries, and not be thrown off by a cow disease that drives up milk -- or a good just being cheaper because of favorable local conditions.

If insulin became expensive during the war, that was only because things became more expensive in general, right? That's what the index should capture: "you need 3x in dollar terms to buy the same stuff in Libya."

How good is your index if you don't capture local shocks?

Beer?

The biggest issue with alcoholic beverages are the taxes that go along with them. Some countries have very high alcohol taxes while others have almost none. That would seriously throw off the PPP calculation.

It needs to be consistent quality and non imported ideally.

Guiness for example is going to cost a lot to ship, or local beer could be very low quality in order to keep the price affordable.

Or just count the cheapest alcohol available

Again it will likley be imported from countries with lower labor costs.

You need something perishable, and of low enough cost that importing is unlikley.

Bread would be a good option but has the issue that it's not as common in Japan as France, it also varies wildley where as a big mac is generally consistent.

A Big Mac, as a branded item, varies by cultural context: in the US, it's super cheap fast food; in Europe it might be late-night after-party food; in Asia, an extravagant treat.

Yes please, it always helps an economics discussion.

Any practical reason you'd want a "non brand related" index? The way I understand it the Big Mac index is pretty good because it casts a wide net from the cost of producing (or importing) food to the price of labour, and everything in between. I doubt you'd get that with a potato.

While it's true that the price of labor, production, transportation, etc, would affect the cost of the Big Mac, it's still ultimately up to McDonalds to set the price, deciding what sort of margin they want from the product, maybe taking into account stuff like brand recognition.

So, using something like the potato would eliminate that sort of "bias" to the product, as no one party controls the potato, and thus couldn't artificially set the price higher at a whim. If the price of the potato rose, it would be because the whole market reacted to some changes to transportation or production costs, not because management has decided that they want to build their brand as being expensive and exclusive (which we know happens with a lot of brand products).

1) I think you're asking too much of what is essentially a silly experiment.

2) What if potatoes become hip?

3) If you want auditable PPP conversion rates: http://data.worldbank.org/indicator/PA.NUS.PPP

There are dozens of varieties of potato. Not all have the same costs to go from seed to market.

What is a 'potato'?

More ubiquitous, Coke: http://blog.premise.com/data/science/2014/09/26/introducing-...