For a lot of the big things we don't have a lot of progress today. Diggers, cars, railroad etc can't improve substantially. I think in the short term we won't

For a lot of the big things we don't have a lot of progress today. Diggers, cars, railroad etc can't improve substantially. I think in the short term we won't get a lot of economic growth. But I think these things happen in phases. We are waiting for the next big breakthroughs. I think Artificial Intelligence, 3D printers, robotics and cheap sustainable power will be the key things to create a new potential for high growth. E.g. if we perfect the technology to 3D print large structures that should bring down costs for house construction a lot. Companies are starting to do this now. But we are in very early stages. AI and more advance robotics will allow us to automate so many tasks we are stuck with using humans now which really limits productivity growth. It is very hard to increase output from a doctor, teacher, lawyer, cab driver, cooks etc at the same rate as say a car factory. This sort of development doesn't go in a gradual phase. As we develop AI we are not gradually making medical diagnosis cheaper or driving cheaper. The huge cost reductions will come when these technologies are completed and can start replacing people at massive scale. Once cars, trucks etc can be driven by and AI, transportation costs will get huge cost reductions. Likewise with medical science. If an AI can diagnose you, one can save enormous amounts of money.