History

Truth: The Strength and Weakness of AI Coding

Zachary Bartsch1 Comment

There was a seismic shift in the AI world recently. In case you didn’t know, a Claude Code update was released just before the Christmas break. It could code awesomely and had a bigger context window, which is sort of like memory and attention span. Scott Cunningham wrote a series of posts demonstrating the power of Claude Code in ways that made economists take notice. Then, ChatGPT Codex was updated and released in January as if to say ‘we are still on the frontier’. The battle between Claude Code and Codex is active as we speak.

The differentiation is becoming clearer, depending on who you talk to. Claude Code feels architectural. It designs a project or system and thrives when you hand it the blueprint and say “Design this properly.” It’s your amazingly productive partner. Codex feels like it’s for the specialist. You tell it exactly what you want. No fluff. No ornamental abstraction unless you request it.

Codex flourishes with prompts like “Refactor this function to eliminate recursion”, or “ Take this response data and apply the Bayesian Dawid-Skene method”. It does exactly that. It assumes competence on your part and does not attempt to decorate the output. It assumes that you know what you’re doing. It’s like your RA that can do amazing things if you tell it what task you want completed. Having said all of this, I’ve heard the inverse evaluations too. It probably matters a lot what the programmer brings to the table.

Both Claude Code and Codex are remarkably adept at catching code and syntax errors. That is not mysterious. Code is valid or invalid. The AI writes something, and the environment immediately reveals whether it conforms to the rules. Truth is embedded in the logical structure. When a single error appears, correction is often trivial.

When multiple errors appear, the problem becomes combinatorial. Fix A? Fix B? Change the type? Modify the loop? There are potentially infinite branching possibilities. Even then, the space is constrained. The code must run, or time out. That constraint disciplines the search. The reason these models code so well is that the code itself is the truth. So long as the logic isn’t violated, the axioms lead to the result. The AI anchors on the code to be internally consistent. The model can triangulate because the target is stable and verifiable.

AI struggles when the anchor disappears

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Drawbacks of Long Term Thinking

Zachary BartschLeave a comment

This post is just some thoughts about perspective. I apologize for any lack of organization.

My academic influences include North, Weingast, Coase, Hayek, the field of Public Choice, and others. I’m not an ‘adherent’ to any school of thought. Those guys just provided some insights that I find myself often using.

What lessons did they teach? Plenty. When I see the world of firms, governments, and other institutions, I maintain a sharp distinction between intention and outcome. Any given policy that’s enacted is probably not the welfare maximizing one, but rather must keep special interests relatively happy. So, the presence of special interests is a given and doesn’t get me riled up. When I see an imperfect policy outcome, I think about who had to be enticed to vote for it. We live in a world where ‘first bests’ aren’t usually on the table.

Historically, or in lower income countries, I think about violence. Their rules and laws are not operating in a vacuum of peaceful consent. There is always the threat of violence. Laws are enforced (or not) conditional on whether and what type of violence that may result. All of the ideal legislation is irrelevant if theft and fraud are the lay of the land.

I think about institutional evolution with both internal and external pressures. I’m a bit worried about the persistence of the US republic, or at least worried for its pro-growth policies. I’m not worried about China in the long run. I don’t think they have the institutions that get them to ‘high income’ status. I do think that they are a tactical concern in the short run and that the government does/will have access to great volumes of resources in the medium run. That’s a bit of a concern. But like I said, I’m not super worried in the long run.

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The US Homicide Rate in 2025 May Have Been the Lowest Ever

Jeremy Horpedahl1 Comment

The following chart merges two data sources to create a long-run series on homicides in the US. Based on early estimates for 2025 from Jeff Asher, the homicide rate may be as low as 4.3 murders per 100,000 population. That would be the lowest since at least 1900, and possibly the lowest US homicide rate ever since the best evidence suggests it was even higher pre-1900. The current record low was 4.4 murders per 100,000, which the US saw in 1955, 1957, and 2014.

Is This the End of the Largest Refugee Crisis in the Americas?

James BaileyLeave a comment

Our 2024 post on the Venezuelan election provides context for this week’s dramatic events:

Venezuela held an election this week; President Maduro says he won, while the opposition and independent observers say he lost. Disputed elections like this are fairly common across the world, but where Venezuela really stands out is not how people vote at the ballot box- it is how they vote with their feet.

Reuters notes that “A Maduro win could spur more migration from Venezuela, once the continent’s wealthiest country, which in recent years has seen a third of its population leave.”

This makes Venezuela the largest refugee crisis in the history of the Americas, and depending on how you count the partition of India, perhaps the largest refugee crisis in human history that was not triggered by an invasion or civil war.

Instead, it has been triggered by the Maduro regime choosing terrible policies that have needlessly and dramatically impoverished the country

Plus some foreshadowing:

I hope that the Venezuelan government will soon come to represent the will of its people. I’m not sure how that is likely to happen, though I guess positive change is mostly likely to come from Venezuelans themselves (perhaps with help from Colombia and Brazil); when the US tries to play a bigger role we often make things worse. But what has happened in Venezuela for the past 10 years is clearly much worse than the “normal” bad economic policies and even democratic backsliding that we see elsewhere. 

Here’s an update on the chart I shared then, showing that the diaspora has continued to swell:

I hope that Venezuela will soon become the sort of country people don’t want to flee. I don’t necessarily expect that it will, but it’s not now a crazy hope:

2025 In Books

James BaileyLeave a comment

What I read in 2025:

Econ Books I Wrote Full Reviews Of:

The Little Book of Common Sense Investing: “John Bogle, the founder of Vanguard, wrote a short book in 2006 that explains his investment philosophy. I can sum it up at much less than book length: the best investment advice for almost everyone is to buy and hold a diversified, low-fee fund that tracks an index like the S&P 500.”

The Little Book that Beats the Market: “Greenblatt offers his own twist on value investing that emphasizes just two value metrics- earnings yield (basically P/E) and return on capital (return on assets). The idea is to blend them, finding the cheapest of the high-quality companies…. Greenblatt’s Little Book is a quick and easy way to learn a bit about value investing, but I think Bogle’s Little Book has the better advice.”

When Genius Failed: “Myron Scholes was on top of the world in 1997, having won the Nobel Prize in economics that year for his work in financial economics, work that he had applied in the real world in a wildly successful hedge fund, Long Term Capital Management. But just one year later, LTCM was saved from collapse only by a last-minute bailout that wiped out his equity (along with that of the other partners of the fund) and cast doubt on the value of his academic work…. The story is well-told, and the lessons are timeless”

The Art of Spending Money: “Its main point is that people tend to be happier spending money on things they value for their own sake- rather than things they buy to impress others, or piling up money as a yardstick to measure themselves against others (this is repeated with many variations). Overall it is well-written at the level of sentences and paragraphs with well-chosen stories and quotes, but I’m not sure what it all adds up to.”

Non-fiction I didn’t previously mention here:

The Napoleonic Wars: A Global History, Alexander Mikaberidze: Aims to educate us about the surprisingly major effects of the Napoleonic Wars outside of Europe. Succeeds wildly; I also learned a lot about the main European theatre. Hadn’t realized how poor British Russian relations were in this era, since they defeat Napoleon together in the end. But they were heading for war early on until a czar was assassinated, then actually went to war in the middle over Sweden and trade. Outside Europe, Britain briefly took Buenos Aires and Montevideo, and accidentally (?) captured Iceland, along with all the French and Dutch overseas colonies.

Talent: How to Identify Energizers, Creatives, and Winners Around the World, Tyler Cowen and Dan Gross: A business book that works best for someone who hires a lot. How to attract and retain diverse candidates, including but not limited to the most-discussed types of diversity. Tyler says that when he lived in Germany people often thought he was Turkish, and one told him to ‘get out of here, you Turk’.

Almost Human: The Astonishing Tale of Homo Naledi and the Discovery That Changed Our Human Story, Lee Berger and John Hawks: The story of how the authors excavated a cave in South Africa that held many remains from a previously unknown type of early human. Good storytelling, good explanations of what we know about early humans from other discoveries, and surprisingly frank discussions of the academic politics behind getting paleontology research funded.

The Ends of the World, Peter Brannen: The book explains Earth’s 5 previous mass extinctions and the geology / science behind how we found out what we know about them. Written explicitly about what all this means for current global warming; see my full review on that here.

Annals of the Former World, John McPhee: New Yorker writer follows geologists from New York to San Fransisco to learn about the land in between. Published as a series of 4 books (Basin and Range, In Suspect Terrain, Rising from the Plains, Assembling California), each one focusing on a different geologist and region. McPhee is known as an excellent stylist but the books are also quite substantive, I feel like I learned a lot.

Fiction

The Works of Dashiell Hammet: My friend Dashiell mentioned that this is who he was named after, and that Red Harvest was a good book of his to start with. He was right, and it lead me to read many others: The Thin Man (you may have heard of Hammet because of the movies adapted from this and The Maltese Falcon), Best Cases of the Continental Op, Honest Gain: Dicey Cases of the Continental Op. Almost every story has a twist more interesting than “the murderer isn’t who you suspected”.

Tress of the Emerald Sea, Brandon Sanderson. Sanderson is one of the most prolific authors of our time, so where do you start with him? He suggests “Mistborn or Tress of the Emerald Sea, depending if they want something more heisty and actiony or something more whimsical.”

The Frugal Wizard’s Handbook for Surviving Medieval England, Brandon Sanderson: Sanderson doing his best impression of Terry Pratchett rewriting Mark Twain’s Connecticut Yankee in King Arthur’s Court, with shades of Scott Meyer’s Off to Be the Wizard.

Janissaries, Jerry Pournelle: What if instead of going to a more primitive world alone, you got sent there with an army?

The Narrow Road Between Desires, Patrick Rothfuss: Enough of an expansion of The Lightning Tree to be worth reading, but at this point anything Rothfuss does other than finally finish Doors of Stone can’t help but be disappointing.

Beguilement, Lois McMaster Bujold: Her Sci Fi works are great so I looked forward to her take on the Fantasy genre, but this turns out to be her take on the Romance genre.

Meta

This year I realized that Hoopla has a lot of books that Libby doesn’t, it is worth checking both apps for a book if you have access to libraries that offer both

Do Tariffs Decrease Prices?

Zachary Bartsch2 Comments

Much of what economics has to say about tariffs comes from microeconomic theory. But it’s mostly sectoral in nature. Trade theory has some insights. But the effects on the whole of an economy are either small, specific to undiversified economies, or make representative agent assumptions that avoid much detail. Given that the economics profession has repeatedly said that the Trump tariffs would contribute to inflation, it seems like we should look at the historical evidence.

Lay of the Land

Economists say things like ‘competition drives prices closer to marginal cost’. Whether the competitor lives abroad is irrelevant. More foreign competition means lower prices at home. But that’s a partial equilibrium story. It’s true for a particular type of good or sector. What happens to prices in the larger economy in seemingly unrelated industries? The vanilla thinking that it depends on various elasticities.

I think that the typical economist has a fuzzy idea that the general price level will be higher relative to personal incomes in some sort of real-wages and economic growth mental model. I don’t think that they’re wrong. But that model is a long-run model. As we’ve discovered, people want to know about inflation this month and this year, not the impact on real wages over a five-year period.

Part of the answer is technical. If domestic import prices go up, then we’ll sensibly see lower quantities purchased. The magnitude depends on the availability of substitutes. But what should happen to total import spending? Rarely do we talk about the expenditure elasticity of prices. Rarely do we get a simple ‘price shock’ in a subsector. It’s unclear that total spending on imports, such as on coffee, would rise or fall – not to mention the explicit tax increase. It’s possible that consumers spend more on imports due to higher prices, or less due to newly attractive substitutes. The reason that spending matters is that it drives prices in other parts of the economy.

For example, I argued previously that tariffs reduce dollars sent abroad (regardless of domestic consumer spending inclusive of tariffs) and that fewer dollars will return as asset purchases. I further argued that uncertainty makes our assets less attractive. That puts downward pressure on our asset prices. However, assets don’t show up in the CPI.

According to the above discussion, it’s unclear whether tariffs have a supply or demand impact on the economy. The microeconomics says that it’s a supply-side shock. But the domestic spending implications are a big question mark.

What is a Tariff Shock?

That’s the title of a recent working paper from the Federal Reserve Bank of San Francisco. It’s a fun paper and I won’t review the entirety. They start by summarizing historical documents and interpreting the motivation of tariffs going back to 1870. They argue that tariffs are generally not endogenous to good or bad moments in a business cycle and they’re usually perceived as permanent. The authors create an index  to measure tariff rates.

Here’s the fun part. They run an annual VAR of unemployment, inflation, and their measure of tariffs. Unemployment in negatively correlated with output and reflects the real side of the economy. Along with inflation, we have the axes of the Aggregate Supply & Aggregate Demand model. Tariffs provide the shock – but to supply or demand?.  Below are the IRF results:

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The Growth of Family Income Isn’t Primarily Explained by the Rise of Dual-Income Families

Jeremy Horpedahl5 Comments

Alex Tabarrok was kind enough to share a chart of mine showing that one-third of families in the US have incomes greater than $150,000. This is a massive increase since the 1960s, or even since the 1980s.

In addition to questions about inflation adjustments and general disbelief, one of the more common questions about this data is how much of it is driven by rising dual-income families, where both the husband and wife work (for purposes of this post, I will look only at opposite-sex couples, since going back to the 1960s this is the only way we can really make consistent comparisons).

In short: most of the growth of high-income families can not be explained by the rise of dual-income families. The basic reason is that the growth in dual-income families had mostly already occurred by the 1980s or 1990s (depending on the measure). So the tremendous growth since about 1990, when just about 15 percent of families were above $150,000 (in 2024 dollars), is better explained by rising prosperity, not a trick of more earners.

You can see this in a number of ways. First, here is the share of married couples where both spouses are working. I have presented the data including all married couples (blue line), as well as only married couples with some earners (gold line), since the aging of the population is biasing the blue-line downwards over time.

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WW II Key Initiatives 3: Kurt Tank Gives Germany a Superior Fighter Plane, the Focke-Wulf 190

Scott BuchananLeave a comment

This is the third in a series of occasional blog posts on individual initiatives that made a strategic (not just tactical) difference in the course of the second world war.

World War II was not only the biggest, bloodiest conflict, in human history. It played a definitive role in giving us the world we have today. Everyone can find something to complain about in the current state of affairs, but think for a moment what the world would be like if the Axis powers had prevailed.

Having control of the air became crucial in the second world war. It meant you could drop bombs on enemy soldiers, ships, tanks, cities, factories, etc., etc. The Germans showed early on how important that can be. Their terror bombing of the Dutch city of Rotterdam compelled the Netherlands to surrender to spare other cities from being likewise bombed, even though the Dutch armed forces could have held out for some time longer. The German breakthrough in their invasion of France in 1940 was facilitated by a concentrated Stuka dive bombing attack on a key sector of the French front lines. The 1940 Battle of Britain was an air war, where the Germans hoped to whittle the British Air Force capability down enough to permit them to invade across the English Channel. And so on.

The main German fighter plane at first was the Messerschmidt Me 109. It was a good plane, although by 1941 the British Spitfire had become a match for it. Both the Me 109 and the Spitfire were designed around in-line engines, where the cylinders were arranged in two long rows in the engine block. That gave a narrow engine, and hence a skinny profile to the airplane, which tended to reduce wind resistance and make for higher speeds. A weak point of all in-line engines is that they need to have a circulating coolant system, going through a radiator, to cool down the engine block from the heat of the internal combustion. This makes for more complicated maintenance and is very vulnerable to being damaged by enemy fire,

Just when the Brits were starting to wrest air superiority back from the Germans, the FW 190 appeared in the skies over France. Allied pilots were shocked. The new German fighter could out-climb, out-roll, and in many cases out-fight the current Spitfire models. This so-called “butcher bird” gave air superiority back to the Germans.

Its remarkable performance was the result of one man’s engineering philosophy and persistence: Kurt Tank, chief designer at the German aircraft manufacturer Focke-Wulf. Tank was a pilot as well as an engineer, with long and varied prior military experience. He chose a radial engine for his plane, to make it more rugged and easy to maintain. With a radial engine, the individual cylinders all stick out from a central crankcase; airflow past the fins on the cylinders cools the engine. Hence, no vulnerable cooling system and radiator. The conventional thinking was that a radial engine was so fat that an airplane using it would have a wide, draggy profile. His ingenious design features allowed him to make a fast, agile plane. However, was an uphill job for Tank to sell his concept to the German military establishment. Eventually, his results spoke for themselves and the Fw 190 was produced. With its critical spots armored, the Fw 190 was hard to kill. Tank deliberately gave a wide stance and long travel to the landing gear, to allow deployment in rough frontline airfields.

The Fw 190 was a superb low-medium altitude fighter, and was also widely pressed into service (due to its rugged design) as a precision bomber on the front lines. Around 20,000 Fw 190s were produced. They shot down many thousands of Allied planes, killed untold thousands of Allied airmen and soldiers, and destroyed thousands of Allied vehicles, mainly on the Eastern Front. It was not enough to change the ultimate outcome of the war, but Tank stretched it out appreciably, by (largely single-handedly) giving the Germans such a versatile and deadly weapon.

An Engineer in 1910 Didn’t Earn $450,000

Jeremy Horpedahl1 Comment

Inflation adjusting income and prices from the past is a common theme in my blog posts, including fact checking of other attempts to do these adjustments. But here is a really novel one, in a viral post from Facebook (which comes from this essay), which claims that a civil engineer earned the equivalent of $450,000 in today’s terms:

Can this be correct? If so, it would represent massive stagnation in incomes over time. Thankfully, there are two major errors, or at least misleading aspects to the calculation.

  1. The listed salary was not one of an “ordinary man” — far from it.
  2. Using gold prices to inflation adjust the incomes is very misleading.

First, the salary: $3,000 per year was definitely not what ordinary men earned. The average wage, for example, for a production worker in manufacturing was 18 cents per hour. You would need to work almost 17,000 hours to earn $3,000 at that wage, which of course is not possible. In reality, the average worker put in 57 hours per week — which means they earned about $500 if they were able to work 50 weeks per year (most probably didn’t). So already we see that the civil engineer working on the Panama Canal is making about 6 times as much as an “ordinary man.” Agricultural workers, the other main industry of 1910, earned about $28 per month ($22 if they also received board) — even less than manufacturing, and only about 1/10 of the engineer

Second, the gold price adjustment is misleading. Yes, in 1910, gold was how we defined currency in the US. But you can’t eat gold, and most people only keep a little gold on hand that can be described as providing services for them (such as jewelry). What people really wanted were real goods and services, and mostly goods. Around 1910, the average American household spent about 40% of their income on food, 23% on housing, and 15% on clothing. Comparing standards of living over time requires us to look at what people spend their money on, not what the currency is denominated in. And that’s what a good consumer price index does: it compares the prices of all consumer spending at different points in time, not just one thing like gold, allowing us to make rough comparisons of income over time.

Using the Measuring Worth historical CPI (which extends the BLS CPI back before 1913), we see that the index was 9.21 in 1910, and it stands at 323.364 in August 2025. So the 18-cent manufacturing wage from 1910 is roughly equivalent to $6.32 in current dollars. The average manufacturing wage today? Around $29. And of course, workers today have a whole range of fringe benefits, worth roughly another $13.58 for private sector workers. This means that an “ordinary man” today working in manufacturing can buy 5-7 times as many real goods and services as his 1910 counterpart for each hour he works. And the work is, of course, much safer today: BLS reports 23,000 industrial deaths in 1913 (61 deaths per 100,000 workers), but only 391 manufacturing deaths in 2023 (0.003 deaths per 100,000 workers).

But what about that extraordinary man in 1910, the civil engineer? How was he doing compared with today? Using the same historical CPI, we can see that $3,000 in 1910 is roughly equivalent to $105,000 today. Not bad! That’s almost exactly the median pay for civil engineers today. But keep in mind the civil engineer working in Panama was an unusually highly paid position. A 1913 report from the American Society of Civil Engineers suggests that most early career civil engineers were making closer to $1,500 per year — half of the Panama engineer. Engineers were also a highly skilled, very rare profession in 1910. And don’t forget that about 10% of the American workers on the Canal died in the construction, mostly from disease so the engineers were probably just as susceptible to death as the laborers.

Finally, we might ask a different question: what if you had held onto gold since 1910? Let’s say your great-great grandfather was a civil engineer, and managed over the course of a few years to save one year’s salary in gold. He even managed to hide it during the 1930s-1970s, when private holding of gold was generally illegal in the US.

How much would that 150 ounces of gold be worth today? That answer is simple: about $615,000 today (gold has gone up a bit just since that calculation was done in May!). But was that a good investment? Not really. A $3,000 investment in the stock market from 1910 to 2024 would be worth about… $120 million (it’s actually a bit more than that, since the market continued to rise after January 2024). Of course, that would have required a bit of active management, since index funds don’t come along until much later. But your great-great grandfather would have been much wiser to set up a trust for you and have it actively managed to approximate the entire US stock market, rather than to bury 150 ounces of gold in his backyard.

Even assuming you lost half the value to management fees, the stock portfolio today would be worth at least 100 times as much as the gold.