Mimi.jl – Next Generation Climate Economics Modeling
07-25, 14:30–15:00 (US/Eastern), Elm B

We will present Mimi.jl, a next generation platform for Integrated Assessment Modelling widely used in climate economics research. The talk will outline technical aspects of the platform, as well as its adoption and impact both on research at universities and in the US federal climate regulation process.


In 2016, the EPA commissioned a report from the National Academy of Sciences on research priorities for improving and updating the Social Cost of Carbon, a metric used by the federal government to account for the impacts of climate change within regulatory impact analyses. One central recommendation from the ensuing National Academies report was to create a common, modular computational platform to better serve modelling work in this area.

Our team created the leading (and probably only) implementation following this call to action: the Mimi Framework. Mimi.jl is entirely implemented in Julia. This talk will present this computational platform, discuss its application, and dive into key design considerations.

The main design constraints for Mimi.jl were that we needed something:
a) computationally fast,
b) simple enough that a lack of significant programming experience is not a barrier for users,
c) that enables a modular work style for distributed, loosely coordinated teams, and
d) that creates a transparent framework enabling easy replication of computational experiments.

We will describe in some detail how we achieved this design using a macro based domain specific language for certain parts of the framework, while at the same time exposing the full power of the Julia language to users. We will also touch on our use of a custom Julia registry as the repository for different modules that different groups can work on, allowing us to use Julia’s package manager to solve the replication problem for computational experiments. We will also discuss a large number of specific design decisions that helped us make the system easy to use for novice programmers.

We will conclude the talk with a discussion of adoption and impact of this platform. We will outline how different groups at a number of leading universities and think tanks have adopted the platform for their work and outline why we believe it will power the next generation of the US federal climate economics work in the regulatory space going forward.

Cora is a Research Assistant at Resources for the Future where she uses the Julia software package, Mimi.jl, for Integrated Assessment Modeling of climate damages and the social cost of carbon. She is a recent graduate of UC Berkeley where she contributed to research in the Energy and Resources Group and was a co-developer of Mimi.jl.

David Anthoff is an environmental economist who studies climate change and environmental policy. He co-develops the integrated assessment model FUND that is used widely in academic research and in policy analysis. His research has appeared in Science, the Journal of Environmental Economics and Management, Environmental and Resource Economics, the Oxford Review of Economic Policy and other academic journals. He contributed a background research paper to the Stern Review and has advised numerous organizations (including US EPA and the Canadian National Round Table on the Environment and the Economy) on the economics of climate change.

He is an assistant professor in the Energy and Resources Group at the University of California, Berkeley. Previously he was an assistant professor in the School of Natural Resources and the Environment of the University of Michigan, a postdoc at the University of California, Berkeley and a postdoc at the Economic and Social Research Institute in Ireland. He also was a visiting research fellow at the Smith School of Enterprise and the Environment, University of Oxford.

He holds a PhD (Dr. rer. pol.) in economics from the University of Hamburg (Germany) and the International Max Planck Research School on Earth System Modelling, a MSc in Environmental Change and Management from the University of Oxford (UK) and a M.Phil. in philosophy, logic and philosophy of science from Ludwig-Maximilians-Universität München (Munich, Germany).

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