Economic researchers from Stanford University and the Massachusetts Institute of Technology have just penned a bit of research with the catchy title “Are Ideas Getting Harder to Find?"

Economics professors Nicholas Bloom, Charles Jones, and John Van Reenen, and PhD candidate Michael Webb say that across a broad range of case studies ideas – and in particular the exponential growth they imply - "are getting harder and harder to find".

For example to maintain Moore's Law -- by which transistor density doubles every two years or so -- it now takes 18 times as many scientists as it did in the 1970s. That means each researcher's output today is 18 times less effective in terms of generating economic value than it was several decades ago.

On an annual basis, research productivity is declining at a rate of about 6.8 percent per year in the semiconductor industry. In other words, we're running out of ideas.

Exponential growth results from the large increases in research effort that offset its declining productivity, the report concludes.