Alex MacKay

State-dependent pricing matters most when trend inflation is high... but that's also when menu cost models are least tractable. I make progress in a new paper, solving the mean field game analytically and deriving a tractable linear Phillips curve for menu cost models:🧵 1/12

@ksangani8 Congrats!

"Incomplete pass-through" (when costs rise 10%, prices rise <10%) is often "complete pass-through in levels" in disguise (costs rise 10 cents/unit, so prices rise 10 cents/unit). Turns out this simple pattern can explain several other features of the data.

Very happy to be joining @UVAEcon as an AP this fall! Thank you to all the amazing people I met on the job market, and to my advisors Florian & Kaspar (not on Twitter), @k_sonin and @evajanster.

They each have a series of papers that cover multiple fields. Check out their websites here: - davidvandijcke.com/research/ - francescoruggieri.github.io They will contribute to an exciting body of research by junior faculty at Virginia Econ! economics.virginia.edu/publications

I'm thrilled that David Van Dijcke (@packlesshepherd) and Francesco Ruggieri (@_FRuggieri) will be joining @UVAEcon this fall. You may know their work! David's JMP extends RDD to distributional outcomes. Francesco's quantifies the effects of taxes for *all* local US governments.

This afternoon: a session on market power on digital platforms.

Happening soon: a session on competition and markups in supply chains.

New NBER WP on algorithmic "coercion." Unlike collusion, coercion can be achieved by a single firm's pricing algorithm. It can be worse for consumers than collusion. @nberpubs

Several observations related to pricing, current technology, and consumer welfare, in this New York Times article.

Same product. Same store. Same time. But on Instacart, different customers may see different prices. My story on a fascinating new experiment from @Groundwork & @ConsumerReports, and on how the idea of a single price is breaking down in the digital age:

Tomorrow, I'm joining a panel of lawyers in NYC to talk about algorithmic collusion and coercion. If you are a interested in the current cases and law around pricing algorithms, you can sign up through the NYSBA website here: nysba.org/events/antitru…

The running list of IO job market candidates for 2025-2026 is live! Fill this out to add your info: forms.gle/SZU7zQGjMbMNRs… Running list here: shoshanavasserman.com/io-jmc/

I am super excited to share a new AI tool, Refine. Refine thoroughly studies research papers like a referee and finds issues with correctness, clarity, and consistency. In my own papers, it regularly catches problems that my coauthors and I missed. 1/

BREAKING NEWS The Royal Swedish Academy of Sciences has decided to award the 2025 Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel to Joel Mokyr, Philippe Aghion and Peter Howitt “for having explained innovation-driven economic growth” with one half to Mokyr “for having identified the prerequisites for sustained growth through technological progress” and the other half jointly to Aghion and Howitt “for the theory of sustained growth through creative destruction.” #NobelPrize

On Monday, October 13, the Nobel Prize in Economics goes to..... What's your prediction? #econtwitter

Using a field experiment, we studied how consumers valued Amazon brands and the extent of self-preferencing by Amazon. We found that Amazon brands bring benefits to consumers, even though they receive a modest prioritization in search rankings.

New evidence from a field experiment finds that Amazon brands generate positive benefits to consumers, despite having similar substitutes and receiving priority in search rankings, from Chiara Farronato, @AndreyFradkin, and @_amackay nber.org/papers/w34135

@BalanceCrafting We did not receive funding from Amazon.

The paper, joint with Chiara Farronato and @AndreyFradkin, is now available as an NBER working paper. @nberpubs link: nber.org/papers/w34135 SSRN: ssrn.com/abstract=53815…

Our findings suggest that policymakers and regulators should exercise caution when the assessing the role of vertically integrated products and services on platforms. Even corrections for self-preferencing can reduce consumer welfare, as we show in the paper.