The Big Mac isn't just a greasy hallmark of modern technological wizardry. It's also a tool for economists to measure the wealth of nations.
Derek Thompson in The Atlantic:
For thousands of years, families devoted the majority of their lives to food. Their waking hours were spent growing and harvesting crops, and most of their income from growing and harvesting went right back into eating. Deep into the late pre-industrial era, unskilled laborers worked grueling hours in fields to earn an income that could often barely feed their family. As Gregory Clark explained in his book A Farewell to Alms, up until the 1700s, the English diet consisted, monotonously, of mostly bread and beer, won only after hours that would make a modern i-banker blush. Food output per person was so meager that “British farm laborers by 1863 had just reached the median consumption of [primitive] forager and subsistence societies.”
Today, food is faster. The Big Mac takes very little work for any one person. It is a product of as much automated manufacturing as human labor. Even U.S. food-prep workers, by some measures the poorest-paid major occupation in America, earn enough to buy more than two Big Macs — that's 1,000+ calories — in just an hour of their work.
McDonald's is a restaurant, but it functions much like a factory. Labor is supported by a deep well of technological innovation, such as vacuum packing, exceptional preservatives, deep freezing, vibrant artificial flavors, and high-speed microwaves. Workers assemble specific parts at great speed to deliver dependable and replicable products. “[McDonald's doesn't] put something on the menu until it can be produced at the speed of McDonald's,” CEO James Skinner said in 2010, sounding not unlike Henry Ford from a century earlier.
In addition to being a technological marvel, the Big Mac moonlights as an economic tool. Every year the Economist calculates a Big Mac Index for the purpose of (being cheeky and) testing what currencies are overvalued compared to the U.S. The results are often illuminating.
More here.