Choosing the future: Markets, ethics and rapprochement in social discounting
Antony Millner (University of California, Santa Barbara and National Bureau of Economic Research) and Geoffrey Heal (Columbia University and National Bureau of Economic Research)
GPI Working Paper No. 13-2021, published in Journal of Economics Literature
This paper provides a critical review of the literature on choosing social discount rates (SDRs) for public cost-benefit analysis. We discuss two dominant approaches, the first based on market prices, and the second based on intertemporal ethics. While both methods have attractive features, neither is immune to criticism. The market-based approach is not entirely persuasive even if markets are perfect, and faces further headwinds once the implications of market imperfections are recognised. By contrast, the ‘ethical’ approach – which relates SDRs to marginal rates of substitution implicit in a single planner’s intertemporal welfare function – does not rely exclusively on markets, but raises difficult questions about what that welfare function should be. There is considerable disagreement on this matter, which translates into enormous variation in the evaluation of long-run payoffs. We discuss the origins of these disagreements, and suggest that they are difficult to resolve unequivocally. This leads us to propose a third approach that recognises the immutable nature of some normative disagreements, and proposes methods for aggregating diverse theories of intertemporal social welfare. We illustrate the application of these methods to social discounting, and suggest that they may help us to move beyond long-standing debates that have bedevilled this field.
Other working papers
Imperfect Recall and AI Delegation – Eric Olav Chen (Global Priorities Institute, University of Oxford), Alexis Ghersengorin (Global Priorities Institute, University of Oxford) and Sami Petersen (Department of Economics, University of Oxford)
A principal wants to deploy an artificial intelligence (AI) system to perform some task. But the AI may be misaligned and aim to pursue a conflicting objective. The principal cannot restrict its options or deliver punishments. Instead, the principal is endowed with the ability to impose imperfect recall on the agent. The principal can then simulate the task and obscure whether it is real or part of a test. This allows the principal to screen misaligned AIs during testing and discipline their behaviour in deployment. By increasing the…
Prediction: The long and the short of it – Antony Millner (University of California, Santa Barbara) and Daniel Heyen (ETH Zurich)
Commentators often lament forecasters’ inability to provide precise predictions of the long-run behaviour of complex economic and physical systems. Yet their concerns often conflate the presence of substantial long-run uncertainty with the need for long-run predictability; short-run predictions can partially substitute for long-run predictions if decision-makers can adjust their activities over time. …
On the desire to make a difference – Hilary Greaves, William MacAskill, Andreas Mogensen and Teruji Thomas (Global Priorities Institute, University of Oxford)
True benevolence is, most fundamentally, a desire that the world be better. It is natural and common, however, to frame thinking about benevolence indirectly, in terms of a desire to make a difference to how good the world is. This would be an innocuous shift if desires to make a difference were extensionally equivalent to desires that the world be better. This paper shows that at least on some common ways of making a “desire to make a difference” precise, this extensional equivalence fails.