If we want to inflate the balloon (grow economy), we need to increase average force exerted on its surface = pressure. We can do that by either increasing the amount of air (increasing money supply) or by increasing air's average kinetic energy = temperature (velocity of money). Actually, we could also increase stretchiness of the surface material (loosen regulation?) but we need to be careful not to go too far or risk exceeding its tensile strength. I wonder how far it would be possible to draw that analogy. Maybe laws of thermodynamics apply to economy?