I've just started reading an interesting book, Brad DeLong's "Slouching Toward Utopia". An interesting bit caught my attention.
He claims that an average unskilled male worker in London in 1870 could use his day's wages to purchase about 5,000 calories of food...and nothing more. That's up from the 3,000 in 1800, or 2,000 in 1600.
By 2012, the average unskilled male worker in London could use a day's wages to buy 2,400,000 calories. I actually did the math on the calories in a bushel of wheat, and the numbers are in that ballpark. Just astonishing.