> World-building for purposes of entertainment generally has little to do with successful prediction
Do you have any evidence that that's true? A decent number of ideas portrayed in science fiction have come true, so clearly successful prediction is going on.
Ultimately, economist or author are both using imagination and extrapolation. I don't see any particular reason to expect better results from the economist.
It's an instance of a more general intuition that excessive consumption of fiction distorts people's beliefs about the world. For example, at some point I saw a study that showed people who watched more TV tended to overestimate rates of violent crime significantly, but I can't find it now.
Anecdotally many people seem to think that human genetic engineering would create permanent class divisions, and they tend to refer to fiction, eg, Gattaca, when asserting this. But that doesn't really make sense. Any rational nation-state would subsidize it massively for the population once it was cheap enough.
Do you have any evidence that that's true? A decent number of ideas portrayed in science fiction have come true, so clearly successful prediction is going on.
Ultimately, economist or author are both using imagination and extrapolation. I don't see any particular reason to expect better results from the economist.