I consider the plausibility of discounting for kinship, the view that a positive rate of pure intergenerational time preference is justifiable in terms of agent-relative moral reasons relating to partiality between generations. I respond to Parfit's objections to discounting for kinship, but then highlight a number of apparent limitations of this approach. I show that these limitations largely fall away when we reflect on social discounting in the context of decisions that concern the global community as a whole, such as (...) those related to global climate change. (shrink)

Climate ethics has been concerned with polluter pays, beneficiary pays and ability to pay principles, all of which consider climate change as a single negative externality. This paper considers it as a constellation of externalities, positive and negative, with different associated demands of justice. This is important because explicitly considering positive externalities has not to our knowledge been done in the climate ethics literature. Specifically, it is argued that those who enjoy passive gains from climate change owe gains not to (...) the net losers, but to the emitters, just as the emitters owe compensation to the net losers for the negative externality. This is defended by appeal to theoretical virtues and to the social benefits of generating positive externalities, even when those positive externalities are coupled with far greater negative externalities. We call this the Polluter Pays, Then Receives ('PPTR', or 'Peter') Principle. This principle is then applied at two levels in the context of Canada. [Open access]. (shrink)

Utility discounting in intertemporal economic modelling has been viewed as problematic, both for descriptive and normative reasons. However, positive utility discount rates can be defended normatively; in particular, it is rational for future utility to be discounted to take into account model-independent outcomes when decision-making under risk. The resultant values will tend to be smaller than descriptive rates under most probability assignments. This also allows us to address some objections that intertemporal considerations will be overdemanding. A principle for utility discount (...) rates is suggested which is rooted in probability discounting. Utility discounting is defended against objections from Parfit (1984) and Broome (2005); Broome (2012). A sample utility discount rate is estimated. [Open access]. (shrink)

The social cost of carbon (SCC) is a central concept in climate change economics. This chapter explains the SCC and investigates it philosophically. As is widely acknowledged, any SCC calculation requires the analyst to make choices about the infamous topic of discount rates. But to understand the nature and role of discounting, one must understand how that concept—and indeed the SCC concept itself—is yoked to the concept of a value function, whose job is to take ways the world could be (...) across indefinite timespans and to rank them from better to worse. A great deal, therefore, turns on the details of the value function and on just what is meant by “better” and “worse.” This chapter seeks to explicate these and related issues, and then to situate them within the evolving landscape of federal climate policy in the United States. (shrink)

This paper distinguishes between five different approaches to social discount rates in climate change economics, criticizes two of these, and explains how the other three are to some degree mutually compatible. It aims to shed some new light on a longstanding debate in climate change economics between so-called “descriptivists” and “prescriptivists” about social discounting. The ultimate goal is to offer a sketch of the conceptual landscape that makes visible some important facets of the debate that very often go unacknowledged.

This paper defends the claim that mere temporal proximity always and without exception strengthens certain moral duties, including the duty to save – call this view Robust Temporalism. Although almost all other moral philosophers dismiss Robust Temporalism out of hand, I argue that it is prima facie intuitively plausible, and that it is analogous to a view about special obligations that many philosophers already accept. I also defend Robust Temporalism against several common objections, and I highlight its relevance to a (...) number of practical policy debates, including longtermism. My conclusion is that Robust Temporalism is a moral live option, that deserves to be taken much more seriously in the future. (shrink)