Considering how technology has come in the last 100 or so years (electric light bulb, telephone, and radio to computers, smartphones, and the internet), it's quite possible that in the next 100 years we will have computers with AI advanced enough to be capable of handling natural language conversations and carrying out complex tasks. Combined with advanced robotics, I can see entire industries being replaced with automation. We wouldn't need people to drive trucks, taxis, buses, trains, or planes. We wouldn't need checkers at grocery stores (assuming they don't get automatically delivered and charged). We wouldn't need thousands of agents at faraway call centers, or workers at factories stamping out products by the thousands. Maybe teachers will be replaced by interactive simulations, and surgeons replaced by intelligent robots. Aside from truly creative professions, there would seem to be very few jobs left for people to do.What would our economy look like in that world?