  Equation (19) has shown that the optimum growth rate of consumption is bounded above by \(\mu\), which explains why \(g^*\) is less than 5% a year for each of the three parametric specifications we have considered. The specifications come from three studies in the welfare economics of global climate change, in which the authors worked with models that are a lot more complex than Ramsey’s. And yet their findings are exactly what his formulation would point to (Dasgupta, 2008), namely, that other things equal, the lower is the chosen value of \(\delta\) and/or the larger is the damage to future well-being that is expected to be caused by global climate change, the greater is the investment level DM should recommend to avert climate change or soften the effects of that change on human well-being. The often shrill debate (e.g., Nordhaus, 2007) on the extent to which global investment should be directed at reducing the deletarious effects of climate change was spurred by differences in model specification among climate-change economists.