It's not a case that there was a golden age when individuals invented things, and nowadays it's teams that do it. In the book i describe one of my heroes, norman barlog who developed these short strawed, high yielding varieties of wheat in mexico. He persuaded india and parkeston to take them up - which effectively kicked off the green revolution. But he didn't persuade india single handedly. This also helps to explain why it tends to be geographically concentrated. If it was a break through by loan individuals, you'd expect innovation to be highly geographically distributed. It tends to be very geographically concentrated where you're surrounded by other inventors, tinkerers...