I’m also persuaded by the median income numbers because they are supported by related measurements of other magnitudes. For example, another way to study economic growth is to look not at median income but at national income, gdp, or gross domestic product, the total production of goods and services. Charles I. Jones, an economist at Stanford University, has “disassembled” American economic growth into component parts, such as increases in capital investment, increases in work hours, increases in research and development, and other factors. Looking at 1950–1993, he found that 80 percent of the growth from that period came from the application of previously discovered ideas, combined with heavy additional investment in education and research, in a manner that cannot be easily repeated for the future. In other words, we’ve been riding off the past. Even more worryingly, he finds that now that we are done exhausting this accumulated stock of benefits, we are discovering new ideas at a speed that will drive a future growth rate of less than one-third of a percent (that’s a rough estimate, not an exact one, but it is consistent with the basic message here). It could be worse yet if the idea-generating countries continue to lose population, as we are seeing in Western Europe and Japan.
We will be discussing about the book for the next few weeks.