Abstract

We organized two evaluations of the paper: "The Macroeconomic Impact of Climate Change: Global vs. Local Temperature"[1]. The paper offers a new approach to estimating the damages of climate change, and their results suggest a substantially higher social cost of carbon. The evaluators are highly positive about nearly all aspects of this work, while offering concrete suggestions for further improvement. To read these evaluations, please see the links below.

Evaluations

1. Evaluator 1

2. Evaluator 2

Overall ratings

We asked evaluators to provide overall assessments as well as ratings for a range of specific criteria.

I. Overall assessment (See footnote1)

II. Journal rank tier, normative rating (0-5): On a ‘scale of journals’, what ‘quality of journal’ should this be published in?2 Note: 0= lowest/none, 5= highest/best.

See “Metrics” below for a more detailed breakdown of the evaluators’ ratings across several categories. To see these ratings in the context of all Unjournal ratings, with some analysis, see our data presentation here.3

See here for the current full evaluator guidelines, including further explanation of the requested ratings.

Evaluation summaries

Anonymous evaluator 1

If I were reviewing this manuscript for an economics journal, I would recommend revise and resubmit, with only minor revisions. Overall, the manuscript is well written in the sense that, since the reader understands immediately what is being estimated and why, that they could be lulled into the trap of thinking that the research is "obvious." The final line before the conclusion is "We conclude that climate change poses a substantial threat to the world economy." But it is the careful empirical construction of the argument, and the identification that a literature has been mechanically missing (netting out) the effect of global temperature shocks while focussing exclusively on local temperature shocks, that gives this manuscript its evident worth.

The manuscript consists of two parts. First, a reduced form impact of global temperature shocks on economic activity at the world and country level. Second, a structural model to convert those estimates into welfare losses and a valuation of the social cost of carbon. The first is the "heart" of the paper in my estimation, while the second half is where many articles stop short - the "so what."

Anonymous evaluator 2

The paper’s empirical innovation is simple: estimating the impacts of temperature on GDP using global time-series data, implicitly capturing the relationship between global temperatures, extreme events, and GDP without modelling all intermediate pathways. This idea, combined with their rigorous analytic approach, may have far-reaching implications due to the huge magnitude of the resulting estimates.

Given the small sample size used to estimate their main results (N<60), robustness checks and cautious inference are essential. I recommend additional checks, which may increase their uncertainty estimates, and could result in either higher or lower estimated impacts.

Metrics

Ratings

See here for details on the categories below, and the guidance given to evaluators.

Journal ranking tiers

See here for more details on these tiers.

Evaluation manager’s discussion (Ben Balmford)

This paper represents a step-change in how the damages of climate change are estimated empirically. Rather than relying solely on local temperature shocks, this paper is able to determine the negative consequences of global temperature shocks, which drastically increases the estimated Social Cost of Carbon. From a policy perspective, this implies that measures to mitigate climate change are even more likely to be welfare-enhancing and are more urgently needed.

Both evaluators provide extremely positive reports on the quality and likely impact of the paper. It clearly makes a very large and important contribution to the literature. The evaluators propose  ways to enhance the paper’s impact with relatively small changes. 

In addition to these revisions to the main paper,  I’d suggest the authors also write a synopsis for laypeople – explaining in simple terms the advances the paper makes  and the key results it offers that should influence future policy. 

Both evaluations, particularly the second, offer numerous – but very do-able – changes which would further enhance the academic quality of what is already a very impressive paper. Finally, in terms of replicability/open science, while evaluator 2 rightly recognises that having a replication package available pre-publication is very good (and unusual), evaluator 1’s remark regarding its completeness is correct.

Process notes

The authors were offered the opportunity to respond to these evaluations, but they declined.