Because of the uncertainty about how to model the growth process of our economy, there is still much confusion about which discount rates should be used to evaluate actions having long-lasting impacts, as in the contexts of climate change, social security reforms or large public infrastructures...

How should one evaluate investment projects whose CCAPM betas are uncertain? This question is particularly crucial for projects yielding long-lasting impacts on the economy, as is the case for example for many green investments. We define the notion of a certainty equivalent beta. We show that...

Because of risk aversion, any sensible investment valuation system should value less Projects that contribute more to the aggregate risk, i.e., that have a larger income elasticity of net benefits. In theory, this is done by adjusting discount rates to consumption betas. But in reality, for...