US long-term productivity growth is unmatched. Most just copy whatever the US invents, this is probably due a combination of US rule of law, being a competive market economy and a well developed financial system
The US has high rates of investment even though the US savings rate is low(even after adding the savings imported from abroad), the efficiency of those investments in the US is quite high, this is probably due having a well developed financial system(Dont laugh, there is a crisis now but over the long-term the US financial system is efficient). Afterall its the financial system who fuels savings into investment and given that the long-term US productivity growth is the highest in the world, the banks and other conduits are doing something right in the long-run
