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Reposted by Pier Paolo Creanza

Danielle Graves Williamson @daniellecgw.bsky.social · 08/09/2026

@ppcreanza.bsky.social, @joaotampellini.bsky.social and I are excited to announce the first iteration of the Junior Economic History Conference, an outlet for early-career researchers to get in-depth feedback on projects: jreconhist.org/flyer/

jreconhist.org

Junior Economic History Conference 2027

Junior Economic History Conference

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Pier Paolo Creanza @ppcreanza.bsky.social · 01/09/2026

First class done and a paper accepted in @jpube.bsky.social ! Great way to start my first semester as a professor 🥳

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Pier Paolo Creanza @ppcreanza.bsky.social · 06/05/2026

My graduation streak is unbroken! Dissertation defended & PhD done ✅👨🏻‍🎓 @princetonecon.bsky.social #EconSky

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Pier Paolo Creanza @ppcreanza.bsky.social · 23/02/2026

I’m happy that we get to stay in Philly!

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Pier Paolo Creanza @ppcreanza.bsky.social · 23/02/2026

Thank you, and I agree with you very much!

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Pier Paolo Creanza @ppcreanza.bsky.social · 23/02/2026

I'm very excited to share that I will start as Assistant Professor of Economics at @swarthmorecollege.bsky.social next fall! I cannot wait to get started!

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Pier Paolo Creanza @ppcreanza.bsky.social · 18/11/2025

In case you missed it last week, here's my JMP 🧵👇

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Joshua Goodman @joshua-goodman.com · 12/11/2025

Danielle Graves Williamson (one of my students and a stunningly original scholar in history/labor, studying "segregation academies" in the US Deep South) bsky.app/profile/dani...

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Danielle Graves Williamson @daniellecgw.bsky.social · 12/11/2025

👋 I'm Danielle, and I'm on the #econjobmarket this year! Let's start with a student describing her segregated school: "The school felt temporary. Built like a warehouse with aluminum siding . . . I had a slipshod education" The twist? The student is white, and her school is private. A JMP 🧵 -->

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

TL;DR 🧠 💡The Great Merger Wave transformed America’s largest firms into Factories of Ideas. 💡 This paper provides the first quantitative study of the GMW’s impact. Innovation effects were large but uneven—especially strong in science-based fields requiring major R&D investment. (12/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

This helps explain how the U.S. entered its Golden Age of Innovation (1900–1940), and why corporate labs like DuPont’s and Bell’s became national assets. It also offers nuanced perspective for today’s debates on Big Tech and innovation. 💻🤖(11/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

👉🏻Big firms can push the frontier but may crowd out others in well-trodden fields. NB: Before WW2, public science was weak: federal R&D funding minimal, universities lagged Europe. Big firms were often the only institutions able to sustain long-term R&D. (10/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

Did these firm-level gains translate into overall progress? Yes, but unevenly. 📈 📉 Across technological domains (1905–1940): 🔹 Breakthroughs ↑ 13 % overall 🔹 Science-based fields (chemistry, electronics, telecom) ↑ 30 % 🔹 Non-science-based fields ↓ 7 % (9/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

I find that: 1️⃣ Firm effects matter greatly in explaining inventive productivity 2️⃣ Lab firms perform better, net of sorting and size/field controls 3️⃣ Joining a lab raises within-inventor productivity 4️⃣ Opening a lab raises firm productivity (8/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

Why these surges? Because mergers gave firms resources to organize research systematically. 🔬 R&D labs spread rapidly after consolidation. Lab-owning firms were substantially more innovative than others. I use an inventor–firm panel and AKM framework to dig deeper. (7/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

🚩 Main finding #1: Consolidation strongly raised innovation for merging firms. Among firms that were already patenting before 1895: 🔹 + 6 patents per year (≈ 4× increase) 🔹 + 0.6 breakthroughs per year (≈ 6× increase) Firms that had never patented became 23 pp more likely to start. (6/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

My analysis combines three approaches: 1️⃣ Firm-level DiD → effect of consolidation on innovation 2️⃣ Inventor–firm AKM model → mechanism through R&D labs 3️⃣ Technology-level DiD → aggregate impact across fields (5/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

To study the GMW, I digitized handwritten merger records from Ralph Nelson (1959) and disambiguated firms and inventors in the patent data (1875–1955). This new dataset links 137,000 firm patent assignees, and 1 million inventors—the first inventor–firm panel before 1940. (4/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

Why is this question so hard to answer? Because firms rarely become big for reasons unrelated to innovation. But here, mergers were driven by a deflationary Depression and a legal loophole. Corporate R&D was only nascent. → Firms merged to survive, not to innovate. (3/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

The largest M&A event in US history opened an era of bigness in American industry 🏭 At the same time, the US entered a golden age of technological innovation 💡 Were these two developments connected? Many influential narratives argue they were, from Chandler to DeLong. (2/13)

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Pier Paolo Creanza @ppcreanza.bsky.social · 11/11/2025

🚀 I'm on the #EconSky Job Market! My JMP asks a classic question: Do large, dominant firms foster or hinder innovation? To study this, I turn to the Great Merger Wave (1895–1904), when >2,600 U.S. firms combined into corporate giants like U.S. Steel and DuPont. A JMP 🧵👇 (1/13)

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Pseudoerasmus @pseudoerasmus.bsky.social · 21/09/2025

From a new paper by @mjdcurtis.bsky.social, David de la Croix, et al. The Little Divergence in 'academic human capital' (kind of publications index) btw northern & southern Europe started ca 1500. Northern Germany diverged from central & southern German areas after the Thirty Years' War.

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Pseudoerasmus @pseudoerasmus.bsky.social · 22/09/2025

Wars were mostly bad for European economic development. Might be obvious to ordinary people, but it's not considered obvious in economic history. But I think it's obvious ;-) Below from @sheilaghogilvie.bsky.social

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Trevon Logan @trevondlogan.bsky.social · 29/09/2025

Good history helps us avoid nostalgia. The great article “Economic History and the Historians” (2020) by Anne McCants reminds me why nostalgia can get us in trouble. Two of her examples are very relevant to today: vaccinations and the popular narrative of some economic “good old days.”

Getting vaccinated is unpleasant. Dying of measles is worse. In the decade before the 1963 vaccine for measles emerged, an average of 475 Americans died from measles every year, most of them children. This (absolute) number had dropped to a low of 1 in 1981, despite a steadily increasing population that might have hypothetically contributed additional cases. Sadly, the number of measles cases in the United States has been steadily climbing upward again because we seem not to remember the ravages of the disease so much as the inconvenience of the shot—even without taking into account the absurd rejection of the solid scientific evidence in favor of vaccinations. Many people still have an elderly relative who survived a bout of severe childhood illness; not one of us has an elderly relative who did not. The blurring of the historical evidence for and against vaccination that arises from strangely incongruous historical narratives allows a seemingly inconsequential but nonetheless deadly nostalgia to run rampant.

Another example of dangerous reverence for the past concerns the flurry of popular enthusiasm lately (at least if the pundits of the 2016 American election are to be believed) for the “good old days” of the 1950s when a family could live securely on just one income (in these nostalgic accounts, that one income is usually a man’s). Lest we forget, these are the same good old days of poor air quality and measles. Maybe trivial in comparison but certainly indicative of the scope of the cognitive problem that nostalgia presents, the average size of a new home built in America in 1950 was 983 sq. ft.; by 2010, the average size had risen to 2,392 sq. ft. Given that families were larger on average in the 1950s than they were in 2010, per capita space allocation had risen even faster than total area. Although we might not need that much personal space, many of us have become used to it. Older furniture now looks tiny compared to what is now on offer in showrooms, whereas older television sets were behemoths with miniscule screens showing programs in glorious black and white.

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David Schindler @david-schindler.de · 29/07/2025

By all indications, last years economics job market was much tougher than any year since the pandemic. But all signs point towards an even worse job market coming up this season. Let me explain.

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Pier Paolo Creanza @ppcreanza.bsky.social · 28/03/2025

Kenneth Sokoloff was an incredibly creative and prolific economic historian—an example anyone should be lucky to follow. Quite fittingly, innovation and business organization were one of his (many) areas of interest, and I'm proud my modest contributions build on his legacy. (2/2) #EconSky

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Pier Paolo Creanza @ppcreanza.bsky.social · 28/03/2025

I'm incredibly honored and grateful to have been awarded the EHA Sokoloff Dissertation Fellowship. Many thanks to the committee for supporting my research on Big Business and Innovation between 1880 and 1940. This is particularly meaningful to me because (1/2)

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Alice Evans @draliceevans.bsky.social · 14/03/2025

Have we passed peak intelligence? In international tests, student scores for reading and maths sunk to a new low. US teens are struggling to concentrate & evaluate information. The excellent @jburnmurdoch.ft.com Warning: this thread is dark 🧵

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Pier Paolo Creanza @ppcreanza.bsky.social · 05/03/2025

Nothing cures pre-presentation jitters like perfecting the aesthetics of the title slide for an inordinate amount of time. #EconSky

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James Feigenbaum @jamesfeigenbaum.bsky.social · 03/03/2025

Today in my econ history PhD class: Politicians and Economic History For better or worse, reasonably sure no one else teaches a lecture like this in any other econ history grad classes

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Florian Ederer @florianederer.bsky.social · 16/12/2024

Mergers are followed by large and persistent increases in lobbying activity, both by individual firms and by industry trade associations, suggesting that firms with market power will also attempt to gain political power. www.nber.org/papers/w33255

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Pier Paolo Creanza @ppcreanza.bsky.social · 12/12/2024

Playing NYT’s Connections is the ultimate exercise in humility, especially in a second language. Why do I even sign up for this daily humbling?

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Pier Paolo Creanza @ppcreanza.bsky.social · 26/11/2024

Yesterday’s stroll along the Schuylkill. I love Philadelphia!

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Wake Forest Department of Economics @wfueconomics.bsky.social · 20/11/2024

Today we had the privilege of hosting Santiago Perez (UC-Davis), who presented his thought-provoking paper, "The G.I. Bill, Standardized Testing, and Socioeconomic Origins of the U.S. Educational Elite Over a Century." 📚 Huge thanks to Santiago for an excellent seminar! 🙌

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Pseudoerasmus @pseudoerasmus.bsky.social · 18/11/2024

There are now FIVE economic-history-related starter packs, listed in order of their emergence...: EH1 @benmschneider.bsky.social bsky.app/starter-pack... EH2 @jamesfeigenbaum.bsky.social bsky.app/starter-pack... Historical Political Economy @magnusrasmussen.bsky.social bsky.app/starter-pack...

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Florian Ederer @florianederer.bsky.social · 18/11/2024

There has been no increase in the economic diversity of elite private and public colleges in the United States over the last century. However, these colleges have become more racially and geographically diverse. www.nber.org/papers/w33164

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Pier Paolo Creanza @ppcreanza.bsky.social · 18/11/2024

Day-to-day, it's easy to feel like you're treading water. I'm actually grateful someone forces me to stop and appreciate what I'm doing and why every few months... #EconSky 📉📈

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Pier Paolo Creanza @ppcreanza.bsky.social · 18/11/2024

It forces me to exit the current rabbit hole and evaluate progress on a larger scale. It doesn't hurt that I'm usually positively surprised by what I find. And it's 100% necessary to not lose sight of the real motivation.

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Pier Paolo Creanza @ppcreanza.bsky.social · 18/11/2024

stepping back and really thinking about (1) What am I doing; (2) Why does this matter in the context of the broader project; (3) Am I really advancing the point of the paper and its contribution?

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Pier Paolo Creanza @ppcreanza.bsky.social · 18/11/2024

Tbh, when I realize it's time to prepare slides for our work-in-progress presentation to faculty and students... I'm usually pretty panicky. I worry I haven't accomplished enough and take it more as nuisance than an opportunity. Yet, every time I end up benefitting a *lot* from the simple act of...

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Pier Paolo Creanza @ppcreanza.bsky.social · 08/11/2024

Hi all, just migrated from #EconTwitter to #EconSky! Here to reconnect with my fellow economists & economic historians, once I find you all again... 😅

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Princeton Economics @princetonecon.bsky.social · 11/11/2024

Allison Green's job market paper studies the role of networks in facilitating migration, using quasi-random ship assignment of US Navy sailors during World War II. allie-e-green.github.io/public/WW2_A...

Allison Green with her job market paper title “Networks and Geographic Mobility: Evidence from World War II Navy Ships,” areas of interest “Labor Economics, Urban Economics, and Economic History,” and letter writers “Leah Boustan (advisor), Ilyana Kuziemko (advisor), and Stephen Redding.”

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Princeton Economics @princetonecon.bsky.social · 11/11/2024

Princeton University's Economics Department is proud to introduce this year's Ph.D. students entering the economics job market. economics.princeton.edu/graduate-pro... Meet our 2024 job market candidates:

Princeton University's Julis Romo Rabinowitz Building with the words "Princeton Economics, 2024 Job Market Candidates."

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Carolyn Tsao @tsaocaro.bsky.social · 11/11/2024

I'm on the job market this year! :) Here's a quick thread on my JMP 🧵

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