The American Academy for the Advancement of Sciences has a brief report on the subject.
http://www.aaas.org/spp/rd/presentat...rcanada908.pdf
Today, R&D funding is 1/3 government and 2/3 private, with the government spending in current dollars relatively flat for the last 30+ years. (see chart on page 5).
The report concludes: Current policy concerns
- Despite large industry investments in R&D, U.S. policymakers are concerned about the state of U.S. innovation and competitiveness.
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U.S. R&D/GDP ratio and other indicators are steady or declining, while other nations are growing (esp. Asian nations) -- (chart on page 7)
IMO, that is a bad trend for our long term economic competitiveness.