US

Climate Change Policies

Question A:

Considering a broad range of costs and benefits is a better tool for guiding climate policy than setting temperature limits (such as 1.5 °C , eg) based on expected links between temperature increases and the extent of environmental harm.

Responses weighted by each expert's confidence

Question B:

Carbon taxes are a better way to implement climate policy than cap-and-trade.

Responses weighted by each expert's confidence

Question A Participant Responses

Participant University Vote Confidence Bio/Vote History
Acemoglu
Daron Acemoglu
MIT
Strongly Disagree
7
Bio/Vote History
There is great urgency. We need a redline, and 1.5C is as good as any, esp taking into account consequences of greater rises for some areas.
Alesina
Alberto Alesina
Harvard Did Not Answer Bio/Vote History
Altonji
Joseph Altonji
Yale
Uncertain
2
Bio/Vote History
The economist in me wants to answer "yes", but the right answer is as much about politics and persuasion as about economics
Auerbach
Alan Auerbach
Berkeley
Agree
5
Bio/Vote History
Autor
David Autor
MIT
Strongly Agree
7
Bio/Vote History
Baicker
Katherine Baicker
University of Chicago
Agree
3
Bio/Vote History
Banerjee
Abhijit Banerjee
MIT
Disagree
7
Bio/Vote History
Its too late and too hard to build s consensus around something more complicated
Bertrand
Marianne Bertrand
Chicago
Disagree
5
Bio/Vote History
Brunnermeier
Markus Brunnermeier
Princeton
Uncertain
9
Bio/Vote History
In general cost-benefit analysis is good, but in this case TAIL RISKS matter much more. They need appropriate overweighting.
Chetty
Raj Chetty
Harvard Did Not Answer Bio/Vote History
Chevalier
Judith Chevalier
Yale
Agree
8
Bio/Vote History
Cutler
David Cutler
Harvard
Uncertain
5
Bio/Vote History
Deaton
Angus Deaton
Princeton
Agree
7
Bio/Vote History
Duffie
Darrell Duffie
Stanford
Strongly Agree
6
Bio/Vote History
Edlin
Aaron Edlin
Berkeley Did Not Answer Bio/Vote History
Eichengreen
Barry Eichengreen
Berkeley
Uncertain
5
Bio/Vote History
Better for policy makers capable of processing a wide range of evidence and acting on it, worse if you just want a focal point for action.
Einav
Liran Einav
Stanford
No Opinion
Bio/Vote History
Fair
Ray Fair
Yale
Uncertain
5
Bio/Vote History
Finkelstein
Amy Finkelstein
MIT Did Not Answer Bio/Vote History
Goldberg
Pinelopi Goldberg
Yale
Strongly Agree
9
Bio/Vote History
Goolsbee
Austan Goolsbee
Chicago
Uncertain
1
Bio/Vote History
Greenstone
Michael Greenstone
University of Chicago
Strongly Agree
10
Bio/Vote History
Hall
Robert Hall
Stanford
Agree
8
Bio/Vote History
A truism valid across a wide range of policy issues
Hart
Oliver Hart
Harvard
Strongly Agree
8
Bio/Vote History
Holmström
Bengt Holmström
MIT
Agree
7
Bio/Vote History
I would include temperature limits, too, in the range of trade-offs
Hoxby
Caroline Hoxby
Stanford
Agree
9
Bio/Vote History
Hoynes
Hilary Hoynes
Berkeley
No Opinion
Bio/Vote History
Judd
Kenneth Judd
Stanford
Agree
9
Bio/Vote History
A temperature target is an inflexible goal and not responsive to tradeoffs that are part of any policy decision.
Kaplan
Steven Kaplan
Chicago Booth
Agree
8
Bio/Vote History
Kashyap
Anil Kashyap
Chicago Booth
Agree
3
Bio/Vote History
Klenow
Pete Klenow
Stanford
Strongly Agree
8
Bio/Vote History
I am not aware of evidence that the costs of temperature change rise discontinuously at any one point.
-see background information here
-see background information here
Levin
Jonathan Levin
Stanford
Agree
3
Bio/Vote History
Maskin
Eric Maskin
Harvard
Agree
6
Bio/Vote History
Nordhaus
William Nordhaus
Yale
Strongly Agree
9
Bio/Vote History
Saez
Emmanuel Saez
Berkeley
Uncertain
5
Bio/Vote History
Samuelson
Larry Samuelson
Yale
Agree
8
Bio/Vote History
Consideration of a broad range of costs and benefits should lie behind any policy. This may well lead to a temperature limit.
Scheinkman
José Scheinkman
Columbia University
Uncertain
6
Bio/Vote History
C-B analysis helpful for comparing different mitigation actions but non-linearities and complementarities demand an overall target
Schmalensee
Richard Schmalensee
MIT
Uncertain
5
Bio/Vote History
Given time horizons, uncertainty, high stakes, cost-benefit analysis is a weak tool; arbitrary limits are not obviously worse.
Shapiro
Carl Shapiro
Berkeley
Uncertain
8
Bio/Vote History
Setting temperature limits seems like a fine way of taking a very complex benefit/cost analysis and putting it into practice.
Shimer
Robert Shimer
University of Chicago
Agree
5
Bio/Vote History
But in the end, implementing optimal policy might be done in part through temperature targets.
Stock
James Stock
Harvard
Agree
9
Bio/Vote History
The cost-benefit is preferred in principle, but a carbon budget approach can be justified as a robust way to guard against unknowns.
Thaler
Richard Thaler
Chicago Booth Did Not Answer Bio/Vote History
Udry
Christopher Udry
Northwestern
Disagree
1
Bio/Vote History
Simplicity may dominate nuance here, if it makes it more feasible to coordinate on better policy.

Question B Participant Responses

Participant University Vote Confidence Bio/Vote History
Acemoglu
Daron Acemoglu
MIT
Agree
4
Bio/Vote History
Of course, they are equivalent under ideal conditions. But a predictable price for carbon is very useful for future planning and as a signal
Alesina
Alberto Alesina
Harvard Did Not Answer Bio/Vote History
Altonji
Joseph Altonji
Yale
Strongly Agree
8
Bio/Vote History
Auerbach
Alan Auerbach
Berkeley
Agree
3
Bio/Vote History
Autor
David Autor
MIT
No Opinion
Bio/Vote History
Baicker
Katherine Baicker
University of Chicago
Uncertain
2
Bio/Vote History
Banerjee
Abhijit Banerjee
MIT
Uncertain
6
Bio/Vote History
Bertrand
Marianne Bertrand
Chicago
Uncertain
6
Bio/Vote History
Brunnermeier
Markus Brunnermeier
Princeton
Agree
10
Bio/Vote History
Tax preferable since marginal abatement cost curve is uncertain, but steeper than marginal damage curve. Latter is flat since CO2 is a stock
Chetty
Raj Chetty
Harvard Did Not Answer Bio/Vote History
Chevalier
Judith Chevalier
Yale
Uncertain
6
Bio/Vote History
Depends. But of course either better than status quo.
Cutler
David Cutler
Harvard
Uncertain
5
Bio/Vote History
Deaton
Angus Deaton
Princeton
Strongly Agree
7
Bio/Vote History
Duffie
Darrell Duffie
Stanford
Uncertain
6
Bio/Vote History
Edlin
Aaron Edlin
Berkeley Did Not Answer Bio/Vote History
Eichengreen
Barry Eichengreen
Berkeley
Agree
5
Bio/Vote History
Einav
Liran Einav
Stanford
Uncertain
1
Bio/Vote History
Fair
Ray Fair
Yale
Agree
5
Bio/Vote History
Finkelstein
Amy Finkelstein
MIT Did Not Answer Bio/Vote History
Goldberg
Pinelopi Goldberg
Yale
Agree
9
Bio/Vote History
Goolsbee
Austan Goolsbee
Chicago
Uncertain
1
Bio/Vote History
Greenstone
Michael Greenstone
University of Chicago
Uncertain
1
Bio/Vote History
Hall
Robert Hall
Stanford
Strongly Agree
1
Bio/Vote History
Cap and trade creates rents that could otherwise be tax revenue
Hart
Oliver Hart
Harvard
Uncertain
5
Bio/Vote History
If we know the marginal cost of emissions a tax is better but if we know the optimal quantity cap and trade is better (see Weitzman).
Holmström
Bengt Holmström
MIT
Agree
6
Bio/Vote History
Hoxby
Caroline Hoxby
Stanford
Agree
5
Bio/Vote History
Hoynes
Hilary Hoynes
Berkeley
Agree
10
Bio/Vote History
Judd
Kenneth Judd
Stanford
Strongly Agree
9
Bio/Vote History
A carbon tax imposes a uniform carbon price across all emissions. How do you cap my car's annual CO2 emissions? Also, we need the revenue.
Kaplan
Steven Kaplan
Chicago Booth
Agree
8
Bio/Vote History
Kashyap
Anil Kashyap
Chicago Booth
No Opinion
Bio/Vote History
i think it is true, but don't know enough to be sure, and suspect the implementation details matter enough to rule out a blanket endorsement
Klenow
Pete Klenow
Stanford
Agree
1
Bio/Vote History
Levin
Jonathan Levin
Stanford
Agree
4
Bio/Vote History
Maskin
Eric Maskin
Harvard
Agree
7
Bio/Vote History
Nordhaus
William Nordhaus
Yale
Strongly Agree
9
Bio/Vote History
Many reasons but one important is to get the revenues to recycle to consumers.
Saez
Emmanuel Saez
Berkeley
Agree
8
Bio/Vote History
Samuelson
Larry Samuelson
Yale
Agree
8
Bio/Vote History
Cap and trade is a reasonably second-best, but a carbon tax is more flexible and potentially more effective.
Scheinkman
José Scheinkman
Columbia University
Agree
5
Bio/Vote History
Carbon taxes greatly simplify market-design albeit with risk of missing desired targets. This can be fixed by changing tax rates.
Schmalensee
Richard Schmalensee
MIT
Uncertain
5
Bio/Vote History
In theory, of course; in practice, cap-and-trade can handle equity/political concerns without compromising efficiency, while tax laws can't
Shapiro
Carl Shapiro
Berkeley
Strongly Agree
10
Bio/Vote History
Shimer
Robert Shimer
University of Chicago
Agree
7
Bio/Vote History
But whatever can achieve a political consensus is better than the alternatives.
Stock
James Stock
Harvard
Strongly Agree
10
Bio/Vote History
Price stability, incentives, administrative advantages, clarity. The main plus of cap&trade is politically it hides the costs.
Thaler
Richard Thaler
Chicago Booth Did Not Answer Bio/Vote History
Udry
Christopher Udry
Northwestern
Agree
4
Bio/Vote History
But I'd take either. Or a combination.