First of all, thank you for such a timely and interesting exposition. I hope a bit of armchair theorizing extrapolating from it can be permitted.

I was struck by the downturn in individuals’ patents before 1929 — during the ‘Roaring Twenties’. Interestingly, the two lines intersect at the Crash.

Individuals’ patents do reflect inventions as ‘get-rich’ schemes. Perhaps in the ’20’s speculation turned people from invention for that purpose? At the same time, the increase businesses’ patents indicates that the co-option of individual inventors was already underway.

In the frenzy of speculation that was the Twenties new ideas for products were the basis for selling stocks in not-yet-established businesses (much like the ‘.com’ frenzy that would come seven decades later). So the demand for new ideas for products could have led to the ‘purchase’ of inventors by speculators.

Later on, in the 1950’s (I forget the exact year) money spent on marketing by businesses in the U.S. exceeded money spent on R & D for he first time — a position it would never relinquish. In the 1980’s industrial giants like GE and GM began making more money from finance than from sales of their products.

Innovation faces lots of competition as a way of generating revenue.