Many people have a dream. With the continuous development of productivity, we will usher in an era of great material abundance. By then, everyone will be equal and a world of great harmony will be created. This dream is very reasonable. The economic development trend we see seems to be like this. Things like private cars and air travel that only a few people could enjoy before are now available to ordinary people. 　　Things that were scarce before will become less scarce in the future. Economics can completely explain this trend: Since there is scarcity, more people want it, and more people are willing to produce it. If there is…