Tuesday 2018-09-25

Jeff Dean has a quick interview and Chad Syverson has one where they both talk about AI -- Dean from an engineering perspective, and Syverson from economics -- which read well together.

Brendan Meade, who is a visiting Harvard faculty member who visited our group in Cambridge for a year and did a bunch of work on earthquake fault simulation. He relayed that in work he'd just done before he came to visit us that he'd replaced the earthquake fault simulation inner loop with, kind of, the world's lamest neural net. It was, you know, four layers of 10 neurons each. And all of a sudden, the thing was like between 10 and 100,000 times faster.
-- Jeff Dean
I think there are a couple of lessons [from previous tech revolutions]. One is that it is not unusual at all to have an extended period — and by extended, I mean measured in decades — of slow pro­ductivity growth, even after a major technology has been commercialized and a lot of its potential has been recog­nized. You saw that with the internal combustion engine, electrification, and early computers. There was about a quarter-century of pretty slow productivity growth before you saw the first acceleration in productivity coming from those technologies.

The second part is that you don't necessarily have just one acceleration and then it's over. There were multiple accelerations from electrification separated by a decade. To me, that says that just because we've had one IT-related acceleration, that doesn't necessarily mean it's over. We can have a second wave. Technologies don't just have to come, give what they have to give, and then go away. You can get multiple waves.

Why that would happen is tied to some of the com­plementarity stories where the first set of gains is driven by direct replacement of the old technology with the new technology. The second wave comes when people recognize there are completely different ways of doing things that the new technology made possible. So it's not that you are simply swapping the old widget for a better one. You are actually doing completely different things now that you have the new technology. This is related to Paul David's widely cited work on how the electric motor didn't just directly replace the steam engine. It eventually led to a complete change in the way factories were designed once people realized you could put a little motor on every single machine. The work didn't have to be stacked on many floors around the single power source any more.

-- Chad Syverson