I think there were a few times when we had blips higher. In the late 1800s and early 1900s and during the space race. I can't find specific data on it, so it is possible that re-written history has led me astray on this point.

I also think, given the pipeline visible in research, we will have a resurgence in a decade or two.

Your assumption is that an increased labor force will result in an increase in productivity.

I wasn't thinking in terms of labor force. I was assuming current research could lead to tech that has a very large impact on our daily lives, and that this impact would increase positive perception the public has of scientists and engineers. I think this happened in the early 1900s and could happen again.