Ashley Langer

This was a great interdisciplinary team to work with! The @uarizona.bsky.social Arizona Institute for Resilience helped bring together economists and scientists to learn about each others work, and this was the outcome.

PFAS in pregnant women’s drinking water puts their babies at higher risk, study finds An innovative study mapped preterm births, low birth weights and infant mortality to municipal water wells downstream from PFAS-contaminated sites. The results show the high cost of PFAS harm.

Mothers who receive drinking water from wells downstream of PFAS contaminated sites have much worse infant health outcomes than similar mothers receiving water from wells upstream of these sites. A full writeup of the study is available here:
theconversation.com/pfas-in-preg...

New paper with Robert Baluja, @boguo.bsky.socialout, Wes Howden, and Derek Lemoine out in PNAS! We use groundwater flow to understand the effect of PFAS contamination in drinking water on infant health outcomes.
www.pnas.org/doi/10.1073/...

The FTC is hiring economists!

Applications due 12/17 so it’s a quick turnaround!

Happy to chat with anyone interested in the position, especially if you have a non-IO background like me…

My group at the University of Illinois is hiring a tenure-track applied economist.

We're especially interested in environmental/public reduced-form rookies with research that complements our group.

Tell your students to apply! #EconSky

www.aeaweb.org/joe/listing....

Thanks for having me! It was a great visit!

If you'll be on the #EconJobMarket this coming year, you may want to join this webinar by @aereorg.bsky.social, titled, "Navigating Uncertain Waters: Advice for the Current Job Market," with Min Gong & @adrienneohler.bsky.social. 29 Sept 2025 @ 11am ET.

This job was central to me becoming an Economist. A great place to try out research and policy analysis!

So sad to hear this! I remember conversations with Michael fondly. Thinking of you and all of his family and friends.

🌎 PhD students: apply to 2025 Berkeley/Sloan Summer School in Environmental/Energy Economics!

🔗 Info + application: www.auffhammer.com/summer-school

📅 Deadline: May 14 | Program: Aug 18–22 at Berkeley

w @auffhammer.bsky.social @severinborenstein.bsky.social, TCarleton, MFowlie, KJack...

13. Excited to see this paper in print soon! Thanks to many for their comments on this! @sebafle.bsky.social @econjim.bsky.social @jonathanelliott.bsky.social @amackay.bsky.social and many others who I don’t think are on here! Special thanks to our editor, John Asker for a great publication process!

Resolving this uncertainty later would lead generators on the exit margin to be more likely to exit! Our point is subtle: this is about delaying uncertainty resolution holding the enforcement probability constant. Yet increasing coal exit seems not to be the current administration’s objective!

The executive order responds to stricter MATS standards that the previous administration announced in 2024. The current executive order highlights that changing administrations also contribute to policy uncertainty.

Along the way to these results, our paper uses generators’ decisions and state mercury policies to estimate generators’ perceived probabilities of MATS enforcement. In 2014, the year the Supreme Court agreed to hear arguments, the perceived enforcement probability fell to 43%!

Our study shows that, in some cases, policymakers may want to prolong uncertainty until after firms need to make decisions to help achieve policy goals. This contrasts with the “real options” result that higher levels of uncertainty cause delays in irreversible decisions.

If coal had been more profitable and exit unlikely, we’d be on the left of the figure and earlier uncertainty resolution would have increased exit. This is more like the case of adoption of a new, costly technology like residential solar. There, resolving uncertainty earlier increases adoption.

Cumulative distribution function of the probability of exit across expected profit shocks. A blue dashed line on the right indicates the profit shock cutoff with ex-post uncertainty resolution leads to high levels of exit. On either side there are red dashed lines that indicate the two profit shock cutoffs with or without certain enforcement. The figure shows that, in expectation across these two potential exit rates, expected exit is lower if uncertainty is resolved earlier.

Why? Cheap natural gas reduced coal’s profitability, leading many coal generators to be close to exiting. Figure 4 of the paper shows that, when such a generator can respond to the court decision, its expected exit probability is lower than if it can’t use this information to decide.

How does this affect generator exit? The delay between announcement and uncertainty resolution caused more generators to exit. Resolving uncertainty 4 years earlier would have lowered generator profits by $1.4 billion but also reduced pollution damages by up to $1.8 billion.

We investigate the EPA’s MATS, which affected coal generators. The original challenges to MATS took 4 years, and generators exited in the interim. With a quicker court decision, they could have taken action in response to the outcome. Instead, they made choices given the expected outcome.

Many executive branch policies are challenged in the courts and these challenges can take years to resolve. Yet firms may need to take irreversible actions before the courts have ruled. How might these actions change if policy uncertainty was resolved more quickly?

2. “Policy Uncertainty in the Market for Coal Electricity: The Case of Air Toxics Standards” looks at the original uncertainty surrounding MATS enforcement. MATS was announced in 2012 with 2016 enforcement. It was challenged in the courts but enforced on time. www.ashleylanger.com/files/policy...

Regulatory Relief for Certain Stationary Sources to Promote American Energy 1.  Coal-fired electricity generation is essential to ensuring that our Nation's grid is reliable and that electricity is affordable for the

Recently the President ordered that coal generators don’t need to comply with the Mercury and Air Toxics Standard (MATS). My forthcoming JPE paper with Gautam Gowrisankaran and Wendan Zhang on uncertainty surrounding MATS, so it seems like it’s time for a thread! www.whitehouse.gov/presidential...

My Stata/C combo didn’t make the paper! 😀

Energy Markets, Decarbonization, and Trade, Spring 2025

🚨Incredible lineup at @nber.org conference this Thurs/Fri 3/20-21: **Energy Markets, Decarbonization, and Trade**

📑Agenda www.nber.org/conferences/...

🎥 Webstream www.youtube.com/nbervideos

Organized w Natalia Ramondo, supported by @sloanfoundation.bsky.social

What’s the paper? Sorry to miss ASSAs this year!

Announcement with text "2025-2026 Transportation Library Travel Grant." Background illustration of a skyline featuring buildings from around the world.

Applications are now open for the 2025 - 2026 Transportation Library Travel Grant. This grant of up to $3,000 supports research projects that benefit from substantial onsite use of our collections. Learn more here: www.library.northwestern.edu/libraries-co...

I've gotten a flurry of requests to access my slides on "Models, Measurement, and Language in Economics" (presumably thanks to the great new year's reading list from @rohitlamba.bsky.social). The file is publicly available via my web page, but here is the link: www.dropbox.com/scl/fi/ntgkb...

🌿 Interested in learning more about the AERE Scholars program? Join us for an info session **today** Dec. 12 at 3pm Eastern/12pm Pacific. 🌿

Register here: https://buff.ly/49zwPMH

Learn more here: https://buff.ly/4grLvzC

Applications for the 2025 cohort will open soon and be due mid-January!

Save the date: 9th Conference on Econometric Models of Climate Change (EMCC) will be at the University of Victoria BC, Canada, Aug. 27-28, 2025.

Come if you want to learn about climate and econometrics (or just want to visit Vancouver Island...) Formal call for papers to follow in 2025. #EconSky

Pre-Doctoral Fellow, Cornell Collaborative for International Development Economics Research (CIDER), Cornell University CIDER: The Cornell Collaborative for International Development Economics Research (CIDER) is a new cross-campus venture at Cornell University encompassing 23 faculty from multiple units across the Cor...

We are hiring predocs!! Come join us: cornell.wd1.myworkdayjobs.com/CornellCaree...

#econsky PLEASE RT!

@aaronsojourner.org what was the version of @econ_ra here again? Sorry I forgot!