  Equation (13) says that if \(\mu \lt \delta , C(t)\) declines to 0 at an exponential rate. Empirically, the pausible case to consider is \(\mu \gt \delta\), which is what we shall do here. It means that the rate of return on investment \((\mu)\) exceeds the rate at which time is discounted \((\delta)\). And that in turn means \(m \gt 0\). Integrating equation (13) yields