Intergenerational equity under catastrophic climate change
Aurélie Méjean (CNRS, Paris), Antonin Pottier (Centre d’Economie de la Sorbonne), Stéphane Zuber (Paris School of Economics - CNRS) and Marc Fleurbaey (Princeton University)
GPI Working Paper No. 5-2020, published in Climatic Change
Climate change raises the issue of intergenerational equity. As climate change threatens irreversible and dangerous impacts, possibly leading to extinction, the most relevant trade-off may not be between present and future consumption, but between present consumption and the mere existence of future generations. To investigate this trade-off, we build an integrated assessment model that explicitly accounts for the risk of extinction of future generations. We compare different climate policies, which change the probability of catastrophic outcomes yielding an early extinction, within the class of variable population utilitarian social welfare functions. We show that the risk of extinction is the main driver of the preferred policy over climate damages. We analyze the role of inequality aversion and population ethics. Usually a preference for large populations and a low inequality aversion favour the most ambitious climate policy, although there are cases where the effect of inequality aversion is reversed.
Other working papers
The Conservation Multiplier – Bård Harstad (University of Oslo)
Every government that controls an exhaustible resource must decide whether to exploit it or to conserve and thereby let the subsequent government decide whether to exploit or conserve. This paper develops a positive theory of this situation and shows when a small change in parameter values has a multiplier effect on exploitation. The multiplier strengthens the influence of a lobby paying for exploitation, and of a donor compensating for conservation. …
Social Beneficence – Jacob Barrett (Global Priorities Institute, University of Oxford)
A background assumption in much contemporary political philosophy is that justice is the first virtue of social institutions, taking priority over other values such as beneficence. This assumption is typically treated as a methodological starting point, rather than as following from any particular moral or political theory. In this paper, I challenge this assumption.
In defence of fanaticism – Hayden Wilkinson (Australian National University)
Consider a decision between: 1) a certainty of a moderately good outcome, such as one additional life saved; 2) a lottery which probably gives a worse outcome, but has a tiny probability of a far better outcome (perhaps trillions of blissful lives created). Which is morally better? Expected value theory (with a plausible axiology) judges (2) as better, no matter how tiny its probability of success. But this seems fanatical. So we may be tempted to abandon expected value theory…