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)

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)

🚩 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)

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)

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)

🚀 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)

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

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

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?

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

First item on the agenda for today: nap!