> We present a wide range of evidence from various industries, products, and firms showing that research effort is rising substantially while research productiv

> We present a wide range of evidence from various industries, products, and firms showing that research effort is rising substantially while research productivity is declining sharply. I think this is a natural course of things that is also suggested by "law of diminishing returns" [1]. As I understand, it's unlikely to maintain the growth multiple with the innovation even if number of people involved in this field is constantly rising. What matters more, however, is if the returns in absolute numbers are greater than what they were before. Making a rough assumption that number of computers in 1970s were 100,000, a performance gain of 10X would have meant a return of 1,000,000. Supposing that number of computers have multiplied by 100,000, even a gain of 1% beats the old figure by long margin. I guess there could be time when gain in absolute numbers won't be significant to justify the added costs but in today's world, it matters to squeeze out small performance gains as long as more and more people are using products of those industries. [1]: https://en.wikipedia.org/wiki/Diminishing_returns https://en.wikipedia.org/wiki/Diminishing_returns