BY FAR the most important input into the process of advancing science and technology is the creative power of human beings or, in economic terms, human capital. As we saw in chapter 3 from the investigations of Derek de Solla Price, the amount of human effort devoted to science and technology appears to have been rising at 4 to 5 percent a year over the past two or three centuries. Enormous advances in knowledge, technology, and material standards of well-being have resulted. Whether scientific and technological effort must continue growing at similar rates to maintain a steady rate of productivity growth--in other words, whether we are on a treadmill and must run ever faster to get ahead--is an open question that can hardly be resolved here. However, we can at least examine how much human capital is devoted to the science and technology enterprise and what growth trends it has exhibited in recent years. We can inquire also into the sources of likely future growth.