Why is it that...?

Why is it that The Economist, one of the most reputable magazines for monetary issues, employs a method based on fast-food products to determine the valuation of global currency?

Ingenious?

Let me elaborate.

Apparently, The Economist has a method called "The BigMac Index". Each year, the magazine collects the prices of Big Mac burgers in various states around the world, and based on those findings estimates the purchasing power of the currency. It's been coined "burgernomics".

What?

Get this. Apparently its kind of accurate.

Joaquin Almunia, the European Commissioner for monetary issues, has already said that the US dollar is under-valued, while the Slovak Krown and Euro are over-valued. According to the "BigMac Index", the Euro is 50% over-valued, and the Slovak Krown is 13% over-valued.

So, what starts in mockery ends in truth?

I guess using a product that a large portion of communities indulge in is a good indicator of purchasing power...or their lack of gastronomic palate.