As Figure 10.9 shows, the pure rate of return on capital—generally 4–5 percent—has throughout history always been distinctly greater than the global growth rate, but the gap between the two shrank significantly during the twentieth century, especially in the second half of the century, when the global economy grew at a rate of 3.5–4 percent a year. In all likelihood, the gap will widen again in the twenty-first century as growth (especially demographic growth) slows.
