Very happy to see that my paper on the effects of wealth taxation on saving has found its new home. Short summary thread below. Special thanks to @DimitrisPapan20, @AnthonyDeFusco, @ProfNoto for bearing with me while I turned a research idea into a JMP!

New evidence shows that incorporation capital requirements substantially reduce entrepreneurial entry without screening on entrepreneurial quality, from Annika Bacher, Andreas Fagereng, @Mariusring, and Ella Getz Wold nber.org/papers/w35780

In the July issue, "Using Rich Lists to Study the Super-Rich and Top Wealth Inequality: Insights from Switzerland" by Enea Baselgia and Isabel Z. Martínez zurl.co/yvbvi

📢 Hiring: Predoctoral Researcher @KOF_ETH to work with me on an SNSF-funded project on profit shifting, tax competition & tax havens. 70%, 1-year, starts Nov 2026. Great fit for anyone into public econ/taxation 👇 jobs.ethz.ch/job/view/12003?…

We're extending access to Claude Fable 5 on all paid plans through July 12.

I'm 75% through my Fable usage on the 20x plan. Here are my impressions: 1. Fable has made incisive product-level judgments I haven't seen from any other model. A good comparison here is the quality of advice my PhD advisor, who won a Nobel in economics, would give on any big picture career or life advice, or any advice on anything in economic history. Fable cannot give Joel's quality of advice on areas in which Joel is an expert, but Fable can give Joel-tier (IMO) advice on areas on which it's an expert through its innate ability PLUS you giving it the right context. 2. I also applied Fable to a wiki-style repo I've created for career planning/strategizing. Some of the advice Fable gave was off base, but this was because of incomplete context in the wiki which I had to remedy rather than Fable's own errors. Fable's advice was quite good after remedying those errors. 3. I used @shadcn 's "improve" skill (github.com/shadcn/improve) on several repos. For me the results were not mindblowing, and it missed some improvements I later found through conversation with Fable. But I still think the skill is a good use of tokens. 4. GPT-Pro *is* comparable to Fable IMO, but since it's harder to use interactively, you can only really use it to get "static" feedback on some code or doc. I had Fable use GPT Pro with Oracle a few times and Fable commented positively on GPT Pro's feedback. 5. I didn't experience a single instance of Fable getting routed to Opus 4.8 by the security classifier. Here's the set of projects to which I used Fable: - A software to automate decision making in causal inference (difference-in-differences, regression discontinuity, etc) - A software to automate my video editing - An economics literature review automation software - Cleanup of my skills repo & optimization of my skills - The aforementioned career planning repo Overall I like Fable, and I'd be very happy if Anthropic consistently gave you 50% of your usage a week with Fable, like they have in this post-export controls trial period. I wouldn't call Fable mind-blowing, but it is better than GPT-5.5, and I'd keep using it consistently if Fable was available on my subscription. The key to optimizing Fable usage is delegating implementation to Opus or Codex.

Documenting strong but slow portfolio responses to a wealth-tax-induced shock to the equity premium that are consistent with adjustment frictions and moderate risk aversion, from Andreas Fagereng, Luigi Guiso, and @Mariusring nber.org/papers/w35262

At @SOLE_Labor_Econ 2019, @san_muly and I met for the first time. Both graduate students, both with a JMP about first jobs. We started working on our paper on FSU immigrants and firms in Israel shortly after. 7 years later it is wonderful to see it come out @JEEA_News 🙏 1/3👇

I’m sure I’m not the first one to say this, but Sergio Correia deserves a prize for his service to the profession. I bet if we added up just the amount of hours that reghdfe has saved economists since it came out, his contribution would be in the top 10 for applied research.

I'm very excited to join the NBER as a Faculty Research Fellow in the Public Economics program! I'm continuously inspired by the great economists I get to interact with at the public meetings. Many thanks to those who nominated me! @nberpubs nber.org/news/nber-appoints-…

Now that there's a $100 ChatGPT Pro tier, it's a no brainer for any economist to choose ChatGPT over Claude at EVERY price point. 1. $100/mo now gets you access to Pro in the web UI, which is invaluable for academic work. See nitter.net/aniketapanjwani/status… for how to optimally use Pro. No Anthropic model compares 2. $20/mo usage with Claude Code is a joke. $20/mo usage with Codex is limiting but not that far off of $100/mo Claude Code usage. I've myself experienced getting capped within an hour at $100/mo with Claude Code with normal usage. With $100/mo with Codex, for the typical economist's usage, you'll never hit 5 hour or weekly limits. 3. GPT 5.4 itself is a much better model than Opus 4.6 for almost everything economists would care about. CC has a better developed plugin ecosystem, subagents in CC work better IMO, and CC IMO is by default a better writer. For anything else - helping you understand papers, write code, plan out structural estimation, think through identification arguments, choose between estimators - I'd prefer Codex. 4. Whenever OpenAI has an outage, they reset usage for everyone, and they keep extending the length to which you get double usage from your subscription (now until end of May!). Anthropic is crunched heavily for compute and seems to be both explicitly ( nitter.net/trq212/status/20372546…) and perhaps surreptitiously (nitter.net/om_patel5/status/20417…) trying to restrict their compute provision. 5. The Codex Desktop app is hands down the best interface for agentic coding right now. The Claude desktop app is probably the worst way to use Claude Code (go to /r/claudecode to read about all the bugs people encounter). There's a dearth of educational material about the Codex Desktop App though (which I will be solving soon) I walk through each of these points in more detail in this YouTube video: piped.video/_oKPa8_7w3Y?si=1Bru… So, what are the switching costs from Claude Code to Codex? > The models feel different/act differently. You have to get used to it. > Skills are an open format, so you can just copy all your skills over to ~/.agents/skills from ~/.claude/skills . There are some CC specific skill features which don't port over 1 to 1 to Codex. > Subagents are configured differently and act differently in CC compared to Codex. > Hooks are experimental in Codex and you have fewer options of harness actions onto which you can configure hooks. I'd say if you haven't yet started with these tools, choose Codex for sure. If you're hitting your Claude Code session limits regularly, then also switch to Codex for sure. If you're not hitting your session limits, or you have a $200+ budget, I'd recommend getting a $20/mo Codex sub and just try it out/feel it out. Codex and CC pair well together anyway, for example by having one write a plan/code and having the other review the plan/code. I have Codex at a $200/mo subscription and CC at a $100/mo subscription - that works well for me, I use Codex 80% of the time and CC 20% of the time.

Very interesting paper on positive fiscal externalities from subsidizing job training programs

I’m on the #EconJobMarket! 🎓 The wealthy earn high returns from their entrepreneurial activities, should we tax them? My JMP shows a top wealth tax creates smaller distortions and stronger redistribution when high returns reflect market power, not just productivity. 👇 More

Finance dept at BI Norwegian Biz School in Norway is hiring! Excellent department that spans many fields, co-located w/ a great econ dept, attractive teaching load, unique admin data opportunities, and v. nice place to live. Job post below ssrn.com/index.cfm/en/janda/…

We are officially on the market this year with 3⃣ positions! Come work with us in 🇨🇦! I am happy to talk to anyone about our department, DMs open! Please share widely and let your students know. PS: You can visit our department if you are coming to this year CSMG, Nov 14-15!

The Veneto Workers Histories (1975–2001) is probably the easiest-to-access population-level employer–employee dataset there is. I’ve put together a page with practical user tips beyond the sparse official docs. 1/3 🧵

New CEPR Discussion Paper - DP20632 Insuring Labor Income Shocks: The Role of the Dynasty @AndreasFagereng, Luigi Guiso @EIEF_Rome, Luigi Pistaferri @SIEPR @Stanford, @mariusring @UTexasMcCombs @UTAustin ow.ly/eQFp50WUmJm #CEPR_HF #EconTwitter

Over the entire past century, Switzerland's wealth was worth ~5x national income. Now wealth is worth 8x NNI. In the July issue, by Enea Baselgia (@eneabaselgia) and Isabel Z. Martínez (@IZMartinez86) zurl.co/Wmbup

🧵1/11 My paper "Default Options and Retirement Saving Dynamics" is forthcoming in the AER! Auto-enrollment is often hailed as behavioral economics' greatest policy success and now covers 100M+ workers worldwide. But: does it actually increase lifetime wealth and welfare?

A few days ago, I told you about the public finance research of the newest John Bates Clark medalist 🏅 Stefanie Stantcheva. There are important open questions in that research, such as, what are the best retirement policies? My paper with Zhixiu YU answers that question. A 🧵

Forthcoming in AEJ: Applied Economics: "The Long-Term Impacts of Mixing the Rich and Poor: Evidence from Conscript Dorms" by Elias Einiö. aeaweb.org/articles?id=10.12…