John Arnold Profile picture
Co-chair of Arnold Ventures. Reality is more nuanced than the headline.
Jun 1 21 tweets 4 min read
After many conversations over past year with friends, business associates & policymakers about the future of AI job disruption, I’ve tried to get my thoughts in order. With the caveat that I have no specific AI expertise, here they are. Comments and corrections encouraged.🧵
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AI coding tools crossed an important threshold over the past year with release of Anthropic's Claude Code. Previously, largely sophisticated autocomplete systems that created code snippets, they’re now agents capable of completing substantial engineering tasks.
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Apr 29 7 tweets 2 min read
Cartels are inherently unstable so it's impressive OPEC has endured 66 years. That said, UAE is 4th country to withdraw in past 7 years. One more and it all may unravel. The emergence of US as largest producer has weakened OPEC; geopolitics might kill it. Who might be next?
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Iran: Saudi and Iran are now in direct regional conflict. Saudi has provided logistical support for US operations while Iran is striking their infrastructure with missiles and drones. Iran has been exempt from quotas since 2018 but what's the point of staying in a Saudi-controlled economic and geopolitical group?
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Mar 29 5 tweets 2 min read
Hard to overstate the role shale gas has played in lowering inflation and spurring American industry. Were we a net importer today as forecast in the 2000s, domestic nat gas & power would be at multiples of current pricing, serving as a huge tax on individuals and companies.
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Given that commodities are priced at the margin, all US gas would be priced based on int'l markets if still a net importer. That price is $15-20 in Western Europe. Instead, the shale revolution happened and gas in the US is $3, roughly unchanged post-Iran.
via @SStapczynski
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Mar 15 5 tweets 2 min read
The Atlantic has a sobering, first-person look at the ramifications of legalized online sports betting. Here are a few of the more telling passages.
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Jan 19 20 tweets 4 min read
Just returned from my first trip to China, mostly looking at the energy and robotics industries. Fascinating. Random observations, both business and general, below...
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The speed to add manufacturing capacity is stunning. Permitting takes weeks. A factory making sophisticated equipment is built in 12 months. An auto plant took 16 months from groundbreaking to first production. Slack in labor market makes it easy to staff and flex employment.
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Dec 13, 2025 8 tweets 2 min read
Have a child going through the selective college admissions process for the first time and the system seems designed specifically to maximize stress for student and parents alike. The process has gotten worse in recent years and will will keep getting worse until it breaks.
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Step 1: Ask a 17-year-old to take a long list of colleges they would be happy to attend and become emotionally committed to just one school for Early Decision because the acceptance rate is higher in the first round, even though odds are they will be rejected.
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Sep 23, 2025 11 tweets 2 min read
Energy costs have tracked inflation historically. That stability is now at risk after scores of projects across every source were cancelled over past decade due to permitting. Without reform, we will not have affordable & reliable energy. A partial list of projects affected:
🧵 Energy projects delayed/cancelled since 2015
Part 1: Nat gas pipelines
1) Atlantic Coast: 1.5 bcf/d, WV-->NC, cancelled
2) Mountain Valley: 2 bcf/d, WV-->VA, delayed
3) PennEast: 1 bcf/d, PA-->NJ, cancelled
4) Constitution: .65 bcf/d, PA-->NY, suspended
Jul 26, 2025 4 tweets 1 min read
Gambling addiction is a slow and quiet killer. You know if someone close to you drinks too much. You don't know if they have a gambling problem. People are embarrassed by their losses. Suicide from gambling debts is rarely directly associated with online sports betting.
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Robinhood now offers sports betting as if it is another form of investing. You can buy a contract on the app that pays out based on a sports outcome as easily as buying stock. It is another step to conflating the concepts of short-term gambling and long-term investing.
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Jul 26, 2025 15 tweets 3 min read
We and @aibm_org hosted an event yesterday about the evidence base and policy options of online sports betting and issued a call for new research. As states continue to legalize, it's important they understand the full ramifications. A thread of some of what I learned.
1/n🧵 Since SCOTUS struck down the federal ban in 2018, 30 states rushed to legalize online sports betting. Many viewed the new revenue source as too tempting to ignore, especially after pandemic hit. Now, some are starting to question if they need more guardrails on the industry.
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Mar 11, 2025 23 tweets 7 min read
Each year, Michael Cembalest at JPM publishes a fantastic, unbiased summary of the state of energy and climate. I find his data invaluable for staying grounded in the facts. Here are 20 slides that stood out to me. His data, my commentary. Link to the report at the end.
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The speed at which solar has won market share for power generation is likely unprecedented for any fuel in history.
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Jan 9, 2025 12 tweets 3 min read
Many social programs are presented as investments that will pay for themselves via better outcomes in the future. But is it true? What if govt funding was tied to outcomes rather than inputs? We @Arnold_Ventures and others tested that model in a first of its kind project. 1/12 Cognitive behavioral therapy (CBT) is a frequently used tool to promote better behavior in many areas. There is promising evidence that it works to reduce recividism. Roca, a leading service provider, worked with Mass General to develop a program for Massachusetts to test. 2/12
Oct 30, 2024 12 tweets 3 min read
This is a great piece on how a nonprofit hospital system, Parkview, amassed 69% market share in Fort Wayne, IN through acquisitions and now abuses that power at the expense of the community. It details many of the worst practices of the industry and is worthy of a thread. 1/12 Image Since 2000, ParkView Hospital has acquired 6 hospitals & 100s of provider locations in/around Fort Wayne. When it couldn't acquire a community hospital voluntarily, it bought local doc practices and siphoned referrals away, crippling its finances until it relented and sold. 2/12 Image
Jun 27, 2024 9 tweets 2 min read
Had the opportunity to do a ride-along with police in LA this week. A few observations about LAPD, and policing in general.
THREAD 1/9 The majority of calls for service had mental illness and/or substance use as a direct cause. The vicious cycle of addiction -> mental illness -> low level crime -> homelessness -> addiction is an incredible driver of social ills without an easy fix. The suffering caused by fentanyl was very clear, and is unlike any other drug epidemic in history. 2/9
Nov 12, 2023 4 tweets 1 min read
The addiction treatment industry has the perfect conditions for fraud:
- fast growing demand
- new reimbursement programs
- desperate clientele
- difficulty to differentiate quality
And sure enough the scammers came for people at their most vulnerable moment. 1/4 It's why we @Arnold_Ventures seed funded the Shatterproof Treatment Atlas, a tool that measures treatment centers against clinical best practices. It helps consumers and payors find quality centers that maximize the chance of success and steer clear of the vultures. 2/4 Image
Sep 8, 2023 6 tweets 2 min read
Americans have been wasting billions a year on cold medicines like Sudafed & Benadryl with the active ingredient phenylephrine, despite conclusive evidence they don't work. But a report published yesterday may finally lead to the removal of these drugs from pharmacy shelves. 1/6 Image It's a great example of the waste in the healthcare system that leads to high costs/poor outcomes. A vote next week will be a big test whether the FDA follows the science or caves to industry pressure. 2/6
Jul 31, 2023 9 tweets 3 min read
Kudos to Austin for recently approving a >50% reduction in the minimum single-family lot size to address rising housing costs. IMO, this is the most impactful change most cities can enact to maintain economic vibrancy and improve residents' standard of living. THREAD 1/n Austin’s reforms are similar to, though not as aggressive, those enacted in Houston 25 years ago. In 1998, Houston reduced minimum lot size from 5000 sq ft to 1400, allowing 3 townhouses or 2 detached houses to be built on land that had previously held one house. 2/n
Jun 15, 2023 6 tweets 2 min read
A long-time criticism of charter schools is that their results don't beat district schools. But the average performance conflates 3 very different models. Deeper analysis of the new CREDO study shows that urban charters create very significant learning gains.
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The charter sector comprises 3 types of charters: urban (54%), exurban (40%), and virtual (6%). Urban charter schools averaged a very significant 29 additional days of learning per year compared to district schools. However, exurban charters, on average, did not outperform.
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May 25, 2023 6 tweets 3 min read
The desire to be independent of FERC jurisdiction has kept ERCOT as a separate grid, but why are the Eastern and Western Interconnects separate and not linked? Turns out to be a remnant of history and geography. 1/6 Image Electrical systems were developed where people lived. In the first half of the 20th century, most people lived in the eastern half of the US or the West Coast (stll largely true). Very few people lived in the Plains because of tough climate, soil and transportation networks. 2/6 Image
May 21, 2023 7 tweets 2 min read
There's a widespread, but incorrect, belief that wind and solar costs are falling and will inevitably keep doing so. The widely underreported reality is that prices are up 30-60% from pre-pandemic lows. The first step to reversing this trend is to acknowledge it. 1/6 This cost increases are well known by industry but absent from public discourse. Two recent studies document it. Here is Lazard's LCOE study, showing the large price declines leading up to 2021 but an increase from $36 to $60 for solar & $38 to $50 for wind over past 2 years. 2/6 Image
Mar 17, 2023 4 tweets 1 min read
It's now clear that in order to meet our goals for affordable, reliable, clean and secure energy, the US must have more interregional transmission lines. Yet, because of past frustrations, there are way too few resources dedicated to modernizing the grid. 1/4 In 2021, I committed to try and build this needed infrastructure, pairing with industry vet Michael Skelly to start Grid United with a stakeholder-first model and funding level that had never before been tried. 2/4
Feb 2, 2023 8 tweets 2 min read
Amgen’s new Humira biosimilar is launching at 2 different list prices: a 5% discount & a 55% discount off Humira’s ≈$80k list price. Exact same drug, very different prices. Yet they'll likely sell much more of the higher $ drug. Welcome to dysfunctional world of drug pricing. 1/ PBMs, the drug buying orgs that insurers either own or contract with, will prefer the higher priced version, as they can negotiate bigger discounts off the list price. Rebate more $ to PBMs and they will steer more patients to the biosimilar. Don't, and they won't. 2/