Purchasing power of burgers

A simple alternative, now that McDonald's has spread to virtually every country on earth, has become to look at what a Big Mac costs, the IW said.

"A particularly hungry American can buy five Big Macs for 11 dollars. If he exchanged the money into Deutsch-marks, his 18 marks in Germany can just barely obtain four Big Macs," the IW said.

Conclusion: based on the Big Mac index, the dollar is undervalued, the institute said.

Americans can get their best Big Mac buy these days in Moscow, where one sandwich costs only about 59 cents.

But Russians must "work nearly two days in order to afford this meaty capitalist achievement - longer than people in any other country", the IW said.