Bill Gross, managing director of US bond manager Pimco, has questioned whether it is worth the US investing huge sums in college education, when state resources are badly needed to pay for job-creating innovations.

In his latest blog, he points out the cost of college tuition has risen at a rate 6% higher than the general rate of inflation for the past 25 years. The average college graduate now leaves with $24,000 of debt. Total student loans now exceed US credit card debt totalling $1 trillion, the equivalent to 7% of US national debt. Noting that college pay has risen rapidly over the years, Gross argues: "Universities are run for the benefit of the adult establishment, both politically and financially, not students."