Prediction: The long and short of it

Antony Millner (University of California, Santa Barbara) and Daniel Heyen (ETH Zurich)

GPI Working Paper No. 7-2020, published in American Economic Journal: Microeconomics

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. So what is the relative importance of short- and long-run predictability? We study this question in a model of rational dynamic adjustment to a changing environment. Even if adjustment costs, discount factors, and long-run uncertainty are large, short-run predictability can be much more important than long-run predictability.

Other working papers

Existential Risk and Growth – Philip Trammell (Global Priorities Institute and Department of Economics, University of Oxford) and Leopold Aschenbrenner

Technologies may pose existential risks to civilization. Though accelerating technological development may increase the risk of anthropogenic existential catastrophe per period in the short run, two considerations suggest that a sector-neutral acceleration decreases the risk that such a catastrophe ever occurs. First, acceleration decreases the time spent at each technology level. Second, since a richer society is willing to sacrifice more for safety, optimal policy can yield an “existential risk Kuznets curve”; acceleration…

Moral demands and the far future – Andreas Mogensen (Global Priorities Institute, Oxford University)

I argue that moral philosophers have either misunderstood the problem of moral demandingness or at least failed to recognize important dimensions of the problem that undermine many standard assumptions. It has been assumed that utilitarianism concretely directs us to maximize welfare within a generation by transferring resources to people currently living in extreme poverty. In fact, utilitarianism seems to imply that any obligation to help people who are currently badly off is trumped by obligations to undertake actions targeted at improving the value…

Choosing the future: Markets, ethics and rapprochement in social discounting – Antony Millner (University of California, Santa Barbara) and Geoffrey Heal (Columbia University)

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. …