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Blog of Tyler Cowen and Alex Tabarrok, both of whom teach at George Mason University.
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My New Jersey history podcast with “Exit Interviews”

2026-02-11 23:17:51

Exit Interviews is a new podcast run by David Piegaro.  I am honored to be one of the first few guests, along with Chris Christie.  Think of this session as “Tyler Cowen as regional thinker.”  Almost 100% fresh material, not to mention some trolling directed at Central and South Jersey, Philly too.  Here is my episode.

Definitely recommended, and let us hope that David Remnick gets on soon to defend the honor of River Vale vs. Hillsdale in Bergen County…

The post My New Jersey history podcast with “Exit Interviews” appeared first on Marginal REVOLUTION.

Immigration and health for elderly Americans

2026-02-11 16:36:28

We measure the impact of increased immigration on mortality among elderly Americans, who rely on the immigrant-intensive health and long-term care sectors. Using a shift-share approach we find a strong impact of immigration on the size of the immigrant care workforce: admitting 1,000 new immigrants would lead to 142 new foreign healthcare workers, without evidence of crowd out of native health care workers. We also find striking effects on mortality: a 25% increase in the steady state flow of immigrants to the US would result in 5,000 fewer deaths nationwide. We identify reduced use of nursing homes as a key mechanism driving this result.

That is from a new NBER working paper by David C. Grabowski, Jonathan Gruber & Brian E. McGarry.

The post Immigration and health for elderly Americans appeared first on Marginal REVOLUTION.

My simple model of fertility decline

2026-02-11 14:04:05

My core model is both simple and depressing.  Fertility rates have declined around the world because birth control technologies became much better and easier to use.  And people — women in particular — just do not want that many kids.

I do understand that better birth control happened a long time ago, for instance birth control pills become widely available in the wealthier countries in the 1960s, or sometimes the 1970s.  Nonetheless the diffusion of new technologies can be very slow, and for norms to shift it can take generational turnover or even a bit more.  Plus “fertility contagion effects” take a long time to work their way fully through the system.

Those long lags may be difficult to swallow, but social science has numerous examples of very long operative mechanisms.  (Just think of how long it took potential migrants to exploit open borders, for instance pre-WWI.)  Furthermore, fertility rates have indeed been falling for a long time in the wealthier countries.

So a lot of women, once they face the realities of the stress and trying to make ends meet, want only one kid.  You end up with a large number of one kid families, some people who never marry/procreate at all, and a modest percentage of families with 2-4 kids.  There are also plenty of cases cases where the guy leaves, self-destructs, or never marries, after siring a single child with a woman.  That gives you the fertility rates we are seeing, albeit with cultural and economic variation.

Richard Hanania considers why income is not the driving force behind the decline, and why the decline is continuing.

Part of this model is that many women just love having a child.  They love “children” so much that a single child fills up their needs and desires.

I see a similar mechanism in my own life.  I very much enjoy having Spinoza around the house, but I have zero desire to take in another canine.  Whenever I want more “dog attention,” I can assure you that the supply is highly elastic.  Similarly, a single kid can take up a lot of your time and affection, again supply is elastic from the side of the kid.  Maybe parents learning how much they can enjoy a single kid has been another cultural lag?

Under my preference-driven model, fertility declines are very difficult to reverse.  I believe that is also consistent with the evidence to date.

So this is a problem we need to worry about.  The asymptote is rather unpleasant, and the path along the way involve less human well-being, possibly less innovation, and maybe some major fiscal crises as well.

As Arnold Kling would say, “Have a nice day.”

The post My simple model of fertility decline appeared first on Marginal REVOLUTION.

Recursive self-improvement from AI models

2026-02-11 02:37:52

With Claude Opus 4.6 and 5.3 Codex, both stellar achievements, the pace is heating up:

OpenAI went from its last Codex release, on December 18, 2025, to what is widely acknowledged to be a much more powerful one in less than two months. This compares to frequent gaps of six months or even a year between releases. If OpenAI can continue at that rate, that means we can easily get four major updates in a year.

But the results from what people in the AI world call “recursive self-improvement” could be more radical than that. After the next one or two iterations are in place, the model will probably be able to update itself more rapidly yet. Let us say that by the third update within a year, an additional update can occur within a mere month. For the latter part of that year, all of a sudden we could get six updates—one a month: a faster pace yet.

It will depend on the exact numbers you postulate, but it is easy to see that pretty quickly, the pace of improvement might be as much as five to ten times higher with AI doing most of the programming. That is the scenario we are headed for, and it was revealed through last week’s releases.

Various complications bind the pace of improvement. For the foreseeable future, the AIs require human guidance and assistance in improving themselves. That places an upper bound on how fast the improvements can come. A company’s legal department may need to approve any new model release, and a marketing plan has to be drawn up. The final decisions lie in the hands of humans. Data pipelines, product integration, and safety testing present additional delays, and the expenses of energy and compute become increasingly important problems.

And:

Where the advance really matters is for advanced programming tasks. If you wish to build your own app, that is now possible in short order. If a gaming company wants to design and then test a new game concept, that process will go much faster than before. A lot of the work done by major software companies now can be done by much smaller teams, and at lower cost. Improvements in areas such as chip design and drone software will come much more quickly. And those advances filter into areas like making movies, in which the already-rapid advance of AI will be further accelerated.

Here is more from me at The Free Press.

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