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tfehring

3,230 karma · joined February 5, 2018

Hi! I'm Tom. I work on quantifying AI risk at the Artificial Intelligence Underwriting Company (aiuc.com). I've previously worked across software engineering, data science, and actuarial roles at organizations including OpenAI, Airbnb, Allianz, and the Harvard-Smithsonian Center for Astrophysics.

Email: [firstname]@fehri.ng

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tfehring··on Weight-based motor vehicle tax
Heavier vehicles still significantly underpay if road maintenance is funded by gas taxes alone, since wear and tear increases in proportion to the fourth power of weight [0] while gas usage only increases linearly or so.

Of course, higher taxes on the heaviest vehicles would just mean higher prices on consumer goods, so this mostly ends up as a subsidy to consumption.

[0] https://en.m.wikipedia.org/wiki/Fourth_power_law

tfehring··on Median Center of Population for the United States: 1880 to 2020 (2021)
I wonder what the median distance from the ocean is and how that's changed over time.
tfehring··on 'Verified human': Worldcoin users queue up for iris scans
It’s completely illegal in the US too. Health insurers are extremely limited in the information they can use to price coverage, and in general they can’t outright deny coverage at all.
tfehring··on There is no data engineering roadmap
A lot of it is dated but the first 3 chapters are still well worth a read for an aspiring DE.
tfehring··on Advice for finding a technical co-founder (2021)
For a pure tech company this might be good advice, but lots of startups require domain expertise from very early on even if that means partnering with a nontechnical founder. E.g., my background is in insurance, I've seen lots of insurtech startups founded by engineers without insurance backgrounds, and in my experience they don't tend to be successful.

In an ideal world you'd want every founder to have background in the relevant industry and strong business sense and the ability to build the product, but being strict about all of those criteria would result in a lot of false negatives.

tfehring··on Larry Ellison: Oracle Database 1,000x Faster Than AWS Aurora
It seems like he was comparing an in-memory columnar datastore to a disk-based row-oriented database for OLAP workloads. So it certainly falls in the "used something in a way it's not meant to be used" bucket, and maybe also in the "very weird edge case" bucket if the implication is that a big company is going to keep a material chunk of its analytics data in RAM.
tfehring··on Google doesn’t want employees working remotely anymore
It's like the paradox of tolerance, right? You can pick the best working environment for yourself, except to the extent that your choice infringes on your coworkers' ability to pick the best working environments for themselves.
tfehring··on Americans have never been so unwilling to relocate for a new job
If their 3.75% mortgage was originally for $1M and has 25 years left, just the cost of giving that up is about $250k. I don't think anyone's giving out a $250k sign-on bonus for a non-executive.
tfehring··on The VC Downturn in 6 Charts
I won't comment on Airbnb because I work there, but for Uber and WeWork, the fact that they're global is a feature in and of itself. It's great that I can request a ride in a city I've never been to, in my native language, without having to look up a local taxi company's phone number or download their app, and with relatively low risk of getting scammed or extorted.

I don't know if Uber or WeWork are or will ever be good investments, but their products are clearly great for users. The fact that they abstract away the underlying hard problems so effectively that they seem like they should be the same app is just a testament to this. But the underlying problems that they're solving are fundamentally very different. WeWork doesn't need Uber's complicated routing and matching algorithms, for example. And unlike WeWork, Uber probably doesn't have architects or construction engineers on staff.

tfehring··on OpenAI’s CEO says the age of giant AI models is already over
I'm using AGI here as arbitrary major improvement over the current state of the art. But given that OpenAI has the stated goal of creating AGI, I don't think it's a non-sequitur to respond to the parent comment's question

> Are you saying instead, that concrete predictive algorithms need improvement or are we lumping the tuning into this?

in the context of what's needed to get to AGI - just as if NASA built an engine we'd talk about its effectiveness in the context of space flight.

tfehring··on OpenAI’s CEO says the age of giant AI models is already over
I'd bet on a 2030 model trained on the same dataset as GPT-4 over GPT-4 trained with perfect-quality data, hands down. If data quality were that critical, practitioners could ignore the Internet and just train on books and scientific papers and only sacrifice <1 order of magnitude of data volume. Granted, that's not a negligible amount of training data to give up, but it places a relatively tight upper bound on the potential gain from improving data quality.
tfehring··on OpenAI’s CEO says the age of giant AI models is already over
I don't think LLMs are over [0]. I think we're relatively close to a local optimum in terms of what can be achieved with current algorithms. But I think OpenAI is at least as likely as any other player to create the next paradigm, and that it's at least as likely as likely as any other player to develop the leading models within the next paradigm regardless of who actually publishes the research.

Separately, I think OpenAI's current investors have a >10% chance to hit the 100x cap on their returns. Their current models are already good enough to address lots of real-world problems that people will pay money to solve. So far they've been much more model-focused than product-focused, and by turning that dial toward the product side (as they did with ChatGPT) I think they could generate a lot of revenue relatively quickly.

[0] Except maybe in the sense that future models will be predominantly multimodal and therefore not strictly LLMs. I don't think that's what you're suggesting though.

tfehring··on OpenAI’s CEO says the age of giant AI models is already over
I think it's unlikely that the first model to be widely considered AGI will be a transformer. Recent improvements to computational efficiency for attention mechanisms [0] seem to improve results a lot, as does RLHF, but neither is a paradigm shift like the introduction of transformers was. That's not to downplay their significance - that class of incremental improvements has driven a massive acceleration in AI capabilities in the last year - but I don't think it's ultimately how we'll get to AGI.

[0] https://hazyresearch.stanford.edu/blog/2023-03-27-long-learn...

tfehring··on OpenAI’s CEO says the age of giant AI models is already over
Related reading: https://dynomight.net/scaling/

In short it seems like virtually all of the improvement in future AI models will come from better algorithms, with bigger and better data a distant second, and more parameters a distant third.

Of course, this claim is itself internally inconsistent in that it assumes that new algorithms won't alter the returns to scale from more data or parameters. Maybe a more precise set of claims would be (1) we're relatively close to the fundamental limits of transformers, i.e., we won't see another GPT-2-to-GPT-4-level jump with current algorithms; (2) almost all of the incremental improvements to transformers will require bigger or better-quality data (but won't necessarily require more parameters); and (3) all of this is specific to current models and goes out the window as soon as a non-transformer-based generative model approaches GPT-4 performance using a similar or lesser amount of compute.

tfehring··on Bad News About Inflation
Based on preliminary BLS data, average hourly earnings are up 6.1% Y/Y in leisure and hospitality, 5.5% in utilities, 5.5% in information, 5.4% in construction, and 4.7% in mining and logging. https://www.bls.gov/news.release/empsit.t19.htm
tfehring··on Ask HN: Best way to “donate” dev hours to charity?
Related reading: https://www.lesswrong.com/posts/3p3CYauiX8oLjmwRF/purchase-f...
tfehring··on A new era of transparency for Twitter
More popular related post: https://news.ycombinator.com/item?id=35391433
tfehring··on Home Prices Fell in February for First Time in 11 Years
> people in Cupertino pay lower overall taxes than people in Austin

Only because most people who can afford to buy in Cupertino aren't paying for it with earned income, right? Google tells me a $2.5M mortgage has minimum payments of $230k a year, anyone who makes enough to afford that is probably paying at least $50k/year in CA state income tax, on top of ~$25k in property taxes. Austin has high property taxes but I don't see them coming anywhere close to that, and the sales tax is lower.

tfehring··on Banking in uncertain times
> Banks engage in maturity transformation, in “borrowing short and lending long.” Deposits are short-term liabilities of the bank; while time-locked deposits exist, broadly users can ask for them back on demand. Most assets of a bank, the loans or securities portfolio, have a much longer duration.

> Society depends on this mismatch existing. It must exist somewhere. The alternative is a much poorer and riskier world, which includes dystopian instruments that are so obviously bad you’d have to invent names for them.

I guess I'll dispute this. It is useful that this mismatch exists, since it (1) lowers the cost of long-term borrowing for mortgagors, businesses, and governments and (2) lowers the (direct and/or opportunity) cost of holding cash. But I don't think society is dependent on this mismatch, and I don't think the alternative would be anywhere near as bleak as Patrick suggests.

If bank regulators changed capital requirements to require banks to fully back deposits with cash equivalents, long-term borrowing would be a lot more expensive, but the market would still clear. There's already plenty of demand for safe long-term debt, and that demand would only increase as long-term interest rates went up. E.g., if checking accounts paid -2% interest and CDs paid 10%, lenders would put less money in checking and more in CDs, even if it meant they would have to sell the CD at a discount if they needed liquidity.

Of course, the US government will take any and every opportunity it can get to indirectly subsidize mortgages, so this is pretty moot in practice.

tfehring··on Duolingo Max, a learning experience powered by GPT-4
I didn't see any pricing information while logged out either, but as soon as I clicked the free trial button and then logged in, the next page that appeared was pricing. It's $12.99/month for an individual plan billed monthly, $6.99/month for an individual plan billed annually, and $9.99/month for a family plan (2-6 members) billed annually. I’m in California in case that matters.
tfehring··on SVB shows that there are few libertarians in a financial foxhole
> No. SVB hid market to market losses by saying "these securities are held to maturity so I don't have to realize losses". THAT is the source of the problem. Not all banks did this.

All major US banks - and all or virtually all US banks in general - have assets that are designated as held to maturity. Continuously marking all assets to market would create massive swings in banks' income and obscure the real gains and losses from their operations.

SVB probably had a somewhat longer asset duration and somewhat lower book yield than US banks on average, since its deposit base grew so quickly in a low interest rate environment in 2020-2021. It also had a higher share of uninsured deposits. But nothing that SVB did was categorically different than other banks, and in the absence of a government backstop, I'm not convinced that any US bank would fare much better if faced with a similar volume of deposit outflows. "Magically" transforming long-dated assets into short-dated liabilities wasn't any kind of malfeasance on SVB's part - it's just how banking works.

tfehring··on Rivian announces 1B gross loss and 600M revenue [pdf]
The gross loss is driven by $920M in losses on firm purchase commitments. As I understand it, Rivian has entered into contracts with suppliers to buy some components needed to manufacture its vehicles at fixed prices over some future period of time, likely several years. If the market prices of those components decrease, the value of those contracts also decreases. In some sense this isn't a "real" loss - Rivian will still be buying the same components, at the same prices, on the same dates that it expected to at the start of the quarter. But the market prices of the components went down, which creates a paper loss, which they have to mark to market.

That also creates a timing mismatch - Rivian's revenue in Q4 was $663M and its cost of revenue was $1663M, but most of the $1663M is associated with vehicles that they haven't delivered or even manufactured yet, so they'll recognize that revenue in future quarters. I don't know what it actually costs them to manufacture one vehicle, but I bet it's a lot less than 2.5x the revenue they get from that vehicle.

Leaving aside the accounting and addressing your real question: From a quick search it looks like Rivian has raised a total of $23B of capital between VC rounds and its IPO, and it has $13B of current assets (mostly cash + inventory) as of 12/31, so that gives it a fairly long runway even at its current burn rate. But its burn rate - loosely, revenue minus expenses - is expected to slow over time, assuming that (1) its revenue grows faster than expenses (it's expecting deliveries to ~double this year, which should increase revenue at a similar rate) and (2) its unit economics work out, i.e., its "true" cost of revenue is less than its revenue.

tfehring··on Stack Overflow is a cacheless, 9-server on-prem monolith
I don’t follow. Holding the total server load constant, why wouldn’t a read-heavy workload benefit more from caching than a more balanced read/write workload?
tfehring··on Place Your Bets
I agree with many of the top-level comments about the relative utility of AI applications and blockchain applications as they exist today. But I'll add another point that no one else seems to have made yet.

The reason for the widespread grift in the crypto space is not just that blockchain applications are a relatively new and overhyped technology. Another huge factor is that many blockchain applications, by their very nature, are designed to circumvent securities regulation in order to raise money from unsophisticated retail speculators.

I'm sure some shitty AI startups will raise capital from retail speculators on crowdfunding platforms and the like. But I expect it to be a lot less widespread compared to the crypto space, and it will happen within the confines of (mostly) US securities regulation, which will mean much better disclosure and much less outright fraud and misappropriation. The main "victims" this time around will be, like, the LPs of second-rate VC funds, and in many cases those fund managers are well aware of all of this but are incentivized to follow the trend anyway.

tfehring··on Planning for AGI and Beyond
Maybe, but regardless of the motivation for their definition, it only makes sense to interpret OpenAI’s claims and ambitions about AGI in the context of their own definition of AGI. If you prefer your own definition, that’s fine! Substitute “median-human-level automaton” or some other less PR-friendly term in OpenAI’s claims about AGI. But while OpenAI say that their goal is (paraphrasing again) to create an aligned AGI, as far as I can tell, they don’t expect or intend the system they create to be sentient.
tfehring··on Planning for AGI and Beyond
There are lots of valid definitions of "AGI" (and of "sentience" for that matter). One that Sam Altman has used in the past is, paraphrasing, a system that can complete many tasks as well as the median human. IMO that's a reasonable definition of AGI, and I don't think it's hard to imagine a system that meets that definition but that isn't sentient in any meaningful sense.
tfehring··on Ask HN: Which big tech companies are still (or permanently) remote?
Airbnb - almost all roles are remote-first and will continue to be remote-first indefinitely. The only caveats I can think of are (1) you have to keep your primary residence in the country the role is based in, and (2) many US employees will be expected to travel to San Francisco for ~2 weeks each year. https://careers.airbnb.com/

(I'm an Airbnb employee.)

tfehring··on Is remote work bad for the economy?
Is that common in practice? The only example I can think of of a smallish town with excellent public schools is West Lafayette, IN. (It looks like Jackson, WY, and Aspen, CO, also have good schools, but I don't think those are very good examples given that they're so far out of reach for typical families.) Other than that, all of the great school districts I know of are in suburbs of big cities, and the small towns I'm familiar with have decent schools at best.

Maybe it will be more common in the future as a result of remote work. But today it seems hard to create the conditions that result in great school districts - i.e., a relatively high concentration of relatively high-income parents who value education - in a small town that's not within commuting distance of a city with good jobs.

tfehring··on Is remote work bad for the economy?
Even outside of tech hubs, the distribution of where those workers end up is pretty different from the the distribution of where they were raised. Not many of my classmates from rural Wisconsin ended up in the Bay Area or New York, but many moved to Chicago or Minneapolis, and of those still in Wisconsin, almost all of those with white-collar jobs are in Milwaukee or Madison. Lots of cities and even many college towns in "flyover country" are doing just fine, but the brain drain from towns with less to offer is very real.

I imagine my hometown would be a very different place if people didn't have to leave to get decent jobs. Though of course there are plenty of other good reasons to leave.

tfehring··on Ask HN: How is the tech market in SF? How does it compare to remote?
For reference, the Detroit was the 5th largest (some sources say 4th largest) city in the US at its peak in the 1950s, similar in size to LA. It's now 27th, with about a third of its peak population.
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