Let's say we have a population of 100 people living in caves, and all they have to entertain themselves is paint on rocks. Then, someone draws a picture on a l

Let's say we have a population of 100 people living in caves, and all they have to entertain themselves is paint on rocks. Then, someone draws a picture on a leaf. Suddenly everyone is snapping those leaf pictures up. Next, someone sticks the leaves together into a book, and that's the next big thing. Finally, someone invents the leaf screen, that is constantly beaming new leafy picture shows into your personal cave. They can't make the leaf screens fast enough to keep up with demand! So, with a constant population we still achieve economic growth.