Myth: Manufacturing's share of the economy has been relatively steady over time.
Fact: Manufacturing's share of the economy has been falling since the early 1950s. Moreover, the decline over the past decade hasn't been any steeper than in the past.
Projection: At this rate, manufacturing drops below 10% of the economy by 2013.
(this is based on newly released data from the BEA for 1947-86. Manufacturing value added is measured as a share of current dollar GDP, which is the right measure to assess the economic impact of manufacturing payroll, profits, etc).