From his Berkeley Economics course: Brad DeLong's Slides: The Invention Transition
- Population (n)--two heads are better than one
- Education (fi)--standing on the shoulders of giants
- Societal openness (li)--how many people can you talk to before being "shown the instruments"
- Means of communication--language, writing, printing, etc....
- If these four are hobbled, the pace of invention will be slow
- Fortunately, no global technological regress (that we remember, at least)
- Only seven known--and disputed--known examples of "local" technological regress
- Iron Dark Age, Medieval Dark Age, Medieval Greenland Vikings, Mayan Heartland, Mississippi Mound-Builders, Easter Island, Flinders Island...
DeLong's "Chains of Innovation" equation has a parameter representing "number of links to others"; the "economy-wide innovation" value tends to infinity as the number of links and "probability of successful transmission" increase.
In my lifetime I've seen the "links to others" bit grow exponentially.
I was struck by the comment that there are only seven known examples of "local" technological regress. Technology is sticky.