A recent book by a U.S. nutritionist pinpoints why large containers of food in the U.S. costs less. The reason is that the U.S. produces an
oversupply of food, according to a number of agricultural economists the author interviewed. The book is:
What to eat, by Marion Nestle (2006). Published by North Point Press, a division of Farrar, Straus and Giroux - New York.
For example: "The deep dark secret of American agriculture (revealed only by agricultural economists behind closed doors) is that there is far too
much food available -- 3,900 calories per day for every man, woman, and child in the country, whereas the average adult needs only a bit more than
half that amount, and children much less. The 3,900 calorie figure is at the high end of the amount available in the food supply of industrialized
countries. Even though these are the available calories ... and not necessarily the amount you actually eat, they reflect substantial excess."
That is from pp. 11-12 of What To Eat. It's a great book on nutrition, and is very well written. For more discussion of this book and related
topics, the author has a blog. Here is a link to a page on that blog which discusses food economics, specifically the recent rise in food prices:
whattoeatbook.com...