I ran across this graph the other day when trying to figure out what goods (by value) that the US imports and exports. If anyone knows the answer to that question, please post it here. However, I keep thinking about this graph because it basically says that scientific and technical services are like food service work for the educated in that it employs more people than the % of total sales predicts it would. - Clare Dibble from Bookmarklet

I think it reflects the extent to which an industry is a "middleman". For example, manufacturing buys stuff, improves it, the resells it, but services don't typically buy as much. The number might be more interesting if the cost of goods were subtracted from the gross sales. - Paul Buchheit from iPhone

What Paul said, not to mention it sort of measures the efficiency that a given industry has in converting its "raw materials" into sales. Manufacturing: Very high efficiency turning raw materials into products / sales. Science? In products terms much lower yield per person hour of effort. Of course that doesn't measure "impact" (which would of course be a nightmare to attempt). - Dan Farmer