  A national saving rate of 40% (eq. 21b) is no doubt high by the standards of contemporary western economies, but there are countries that in recent years have achieved 40–45% saving rates (China is a prominent example). A figure of 67% for \(s^*\) (eq. 21a) is higher than the saving rate in any country, but is not beyond belief. The truly outlandish figures is 98% (eq. 21c). It is outlandish especially because the figure is the optimum saving rate no matter how small \(K(0)\) happens to be.  Admittedly, the model here (eqs. 11a–b) is phenomenally stylized, but it does bring out sharply the observation of Koopmans (1965), that it is foolish to assume \(\delta = 0\) (or close to 0) without first checking its possible consequences for the distribution of well-being across the generations.