The previous chapter, in pointing out the macrodynamic properties of an economy like that of the United States, has suggested that it is possible for a society to exercise some choice, through its political system, as to the rate at which the economy will expand. But is that choice unbounded? This is the question which this chapter starts off by exploring. The concept of a potential growth rate is introduced, with the factors which may determine that potential growth rate – the availability of manpower and the rate of technological change – then analyzed. The conclusion reached is that while the potential growth rate may well exist as an asymptotic limit which the economy can only approach, this is not the reason why the rate of economic expansion is usually held in check by the political authorities. Their reluctance to use the control they have to achieve a higher secular growth rate is due instead to the difficulty of getting the economy off the dead center established by the existing secular growth rate. Indeed, any change in the aggregate growth rate – if it is to lead to a new secular rate of expansion and not just represent another cyclical movement – will require a carefully orchestrated series of adjustments, not only on the part of government but in the other sectors of the economy as well.