Category: Science

Population Growth and Technological Change: One Million B.C. to 1990

That is an older paper by the excellent Michael Kremer, worth keeping in mind, here is the abstract:

The nonrivalry of technology, as modeled in the endogenous growth literature, implies that high population spurs technological change. This paper constructs and empirically tests a model of long-run world population growth combining this implication with the Malthusian assumption that technology limits population. The model predicts that over most of history, the growth rate of population will be proportional to its level. Empirical tests support this prediction and show that historically, among societies with no possibility for technological contact, those with larger initial populations have had faster technological change and population growth.

This bears on my earlier Bloomberg column, today cited by Mike Lee, suggesting that having more children is likely to help out on the climate change issue.

The best sentence I read today

Mark [Lutter] has a PhD in Economics from George Mason, but don’t let that fool you into thinking he’s conventional.

Here is the full bit:

Mark Lutter (29) and Tamara Winter (23), United States
Mark and Tamara are building charter cities — a concept where cities are governed by their own charter rather than general law. Imagine a world with dozens of new cities, each with their own distinct style, governance and populace. Mark and Tamara are working to make that vibrant future a reality.

Noteworthy: Mark has a PhD in Economics from George Mason, but don’t let that fool you into thinking he’s conventional. He’s a disagreeable, life-long adventurer. He decided to do his own thing after questioning the profit share in his previous company. He moved to Honduras while it was the murder capital of the world. Now he’s stumbling through Africa looking for city settlers.

They are part of the third cohort of Pioneer winners, congrats to Justin Zheng too and all the others, read through the list for some fascinating ideas and projects to come.  Tamara is a Mercatus alum, follow her here on Twitter, here is Mark.  Here is their institutional website.  Here is various information about Pioneer — apply!

Are all humans South Africans?

Africa was the birth-place of Homo sapiens and has the earliest evidence for symbolic behaviour and complex technologies. The best-attested early flowering of these distinctive features was in a glacial refuge zone on the southern coast 100–70 ka, with fewer indications in eastern Africa until after 70 ka. Yet it was eastern Africa, not the south, that witnessed the first major demographic expansion, ~70–60 ka, which led to the peopling of the rest of the world. One possible explanation is that important cultural traits were transmitted from south to east at this time. Here we identify a mitochondrial signal of such a dispersal soon after ~70 ka – the only time in the last 200,000 years that humid climate conditions encompassed southern and tropical Africa. This dispersal immediately preceded the out-of-Africa expansions, potentially providing the trigger for these expansions by transmitting significant cultural elements from the southern African refuge.

That is from Teresa Rito, et.al., in Nature, vis Charles Klingman.

Density is Destiny: Economists Predict the Far Future

In a paper that just won the JPE’s Robert Lucas Prize, Desmet, Krisztian Nagy and Rossi-Hansberg model the evolution of the world economy over the next 400-600 years! Is it laughable or laudatory? I’m not entirely sure. The paper does have an insight that I think is very important, in addition to a number of methodological advances.

If we look around the world today we see that the places with the densest populations, such as China and India, are poor. But in the long-run of history that doesn’t make sense. As Paul Romer, and others, have emphasized, ideas are the ultimate source of wealth and more people means more ideas. As a result, innovation and GDP per capita should be higher in places and times with more people. The fact that China and India are poor today is an out-of-equilibrium anomaly that happened because they were slower than the West to adopt the institutions of free markets and capitalism necessary to leverage ideas into output. China and India weren’t relatively poor in the past, however, and they won’t be relatively poor in the future. With that in mind, a key long-run prediction of Desmet, Krisztian Nagy and Rossi-Hansberg becomes clear. If people are not allowed to migrate then the places that are densest today will not only equal the West, they will overtake the West in innovation and productivity.

One of the key determinants of these patterns is the correlation between GDP per capita and population density. As we mentioned above, the correlation is negative and weak today, and our theory predicts that, consistent with the evidence across regions in the world to-day, this correlation will become positive and grow substantially over the next six centuries, as the world becomes richer. Two forces drive this result. First, people move to more productive areas, and second, more dense locations become more productive over time since investing in local technologies in dense areas is, in general, more profitable. Migration restrictions shift the balance between these two mechanisms. If migration restrictions are strict, people tend to stay where they are, and today’s dense areas, which often coincide with developing countries, become the most developed parts of the world in the future…. In comparison, most of today’s high-productivity, high-density locations in North America, Europe, Japan, and Australia fall behind in terms of both productivity and population.

Thus, if migration restrictions are strict, density is destiny and the dense parts of the world will rule. But what if migration restrictions are loosened?

… if migration restrictions are lifted, then people today move to the high-productivity regions such as Europe and the United States and these regions become denser and so remain the high-productivity regions in the future. World welfare in this scenario goes up by a factor of three.

It’s much better to remove migration restrictions today because we get to a much richer world, faster. In addition, population is better distributed in accordance with natural amenities. All is not perfectly rosy, however, in the free migration scenario. So let’s conclude with a few sentences that would make Hari Seldon proud.

[in the free migration scenario]…growth in utility drops substantially in the short run as many people move to areas with high real GDP; hence these areas be-come more congested and become worse places to live (lower amenities). This initial loss in growth is, however, compensated in the long run by a large surge in productivity growth after year 2200.

The rise of the temporary scientist

Here is a new and important piece on the economics of science, from Staša MilojevićFilippo Radicchi, and John P. Walsh:

Contemporary science has been characterized by an exponential growth in publications and a rise of team science. At the same time, there has been an increase in the number of awarded PhD degrees, which has not been accompanied by a similar expansion in the number of academic positions. In such a competitive environment, an important measure of academic success is the ability to maintain a long active career in science. In this paper, we study workforce trends in three scientific disciplines over half a century. We find dramatic shortening of careers of scientists across all three disciplines. The time over which half of the cohort has left the field has shortened from 35 y in the 1960s to only 5 y in the 2010s. In addition, we find a rapid rise (from 25 to 60% since the 1960s) of a group of scientists who spend their entire career only as supporting authors without having led a publication. Altogether, the fraction of entering researchers who achieve full careers has diminished, while the class of temporary scientists has escalated. We provide an interpretation of our empirical results in terms of a survival model from which we infer potential factors of success in scientific career survivability. Cohort attrition can be successfully modeled by a relatively simple hazard probability function. Although we find statistically significant trends between survivability and an author’s early productivity, neither productivity nor the citation impact of early work or the level of initial collaboration can serve as a reliable predictor of ultimate survivability.

As Raghuveer Parthasarathy argues in his excellent blog post: “…small groups may be innovative, but they are the hardest to sustain given the randomness of scientific funding.”

For the pointer I thank Raghuveer Parthasarathy.

Should climate change limit the number of kids you have?

No, or so says I in my latest Bloomberg column., here is the closing bit:

Let’s not give up by ceasing to have children.

Finally, leave aside the implausibility of these arguments and consider their assumptions. What you’ll find is zero-sum thinking, negative value judgments about large families, and an attempt to use guilt and shame to steer social and environmental policy. I suspect that is why these arguments are finding some traction, not because they are the result of any careful cost-benefit calculations.

So if you are both worried about climate change and considering starting a family, I say: Put aside the unhelpful mess of emotions some participants in this debate are trying to stir up. Instead, focus on how your decision might boost future innovation. As a bonus, you might find that one of the better approaches to climate change is actually pretty fun.

Super simple arguments, with credit to Paul Romer and Alex T. and Bryan and Ross Douthat as well.

The third cohort of Emergent Ventures recipients

As always, note that the descriptions are mine and reflect my priorities, as the self-descriptions of the applicants may be broader or slightly different.  Here goes:

Jordan Schneider, for newsletter and podcast and writing work “explaining the rise of Chinese tech and its global ramifications.”

Michelle Rorich, for her work in economic development and Africa, to be furthered by a bike trip Cairo to Capetown.

Craig Palsson, Market Power, a new YouTube channel for economics.

Jeffrey C. Huber, to write a book on tech and economic progress from a Christian point of view.

Mayowa Osibodu, building AI programs to preserve endangered languages.

David Forscey, travel grant to look into issues and careers surrounding protection against election fraud.

Jennifer Doleac, Texas A&M, to develop an evidence-based law and economics, crime and punishment podcast.

Fergus McCullough, University of St. Andrews, travel grant to help build a career in law/history/politics/public affairs.

Justin Zheng, a high school student working on biometrics for cryptocurrency.

Matthew Teichman at the University of Chicago, for his work in philosophy podcasting.

Kyle Eschen, comedian and magician and entertainer, to work on an initiative for the concept of “steelmanning” arguments.

Here is the first cohort of winners, and here is the second cohort.  Here is the underlying philosophy behind Emergent Ventures.  Note by the way, if you received an award very recently, you have not been forgotten but rather will show up in the fourth cohort.

Injectable NanoParticles Let Mice See Near InfraRed!

Wow! This paper, Mammalian Near-Infrared Image Vision through Injectable and Self-Powered Retinal Nanoantenna, newly published in Cell seems like something from the future. Basically they injected nano-particles that convert near infra-red to visible light into the retinal layer of the eye in mice enabling the mice to see in the near infra-red.

…we developed ocular injectable photoreceptor-binding upconversion nanoparticles (pbUCNPs). These nanoparticles anchored on retinal photoreceptors as miniature NIR light transducers to create NIR light image vision with negligible side effects. Based on single-photoreceptor recordings, electroretinograms, cortical recordings, and visual behavioral tests, we demonstrated that mice with these nanoantennae could not only perceive NIR light, but also see NIR light patterns. Excitingly, the injected mice were also able to differentiate sophisticated NIR shape patterns. Moreover, the NIR light pattern vision was ambient-daylight compatible and existed in parallel with native daylight vision. This new method will provide unmatched opportunities for a wide variety of emerging bio-integrated nanodevice designs and applications.

…In summary, these nanoparticles not only provide the potential for close integration within the human body to extend the visual spectrum, but also open new opportunities to explore a wide variety of animal vision-related behaviors. Furthermore, they exhibit considerable potential with respect to the development of bio-integrated nanodevices in civilian encryption, security, military operations, and human-machine interfaces, which require NIR light image detection that goes beyond the normal functions of mammals, including human beings. Moreover, in addition to visual ability enhancement, this nanodevice can serve as an integrated and light-controlled system in medicine, which could be useful in the repair of visual function as well as in drug delivery for ocular diseases.

The researchers are mostly from China. It sometimes seems that Chinese researchers are naturally extropian, bolder and more optimistic about technology, human extension and the future than anyone else in the world.

Hat tip: Paul Kedrosky.

How to improve the tenure process

Next, institutions must heed growing calls to abandon paper counting and similar metrics for evaluating researchers. One alternative approach, the Rule of Five, demonstrates a clear commitment to quality: candidates present their best five papers over the past five years, accompanied by a description of the research, its impact and their individual contribution. The exact numbers are immaterial: what matters is the focus on quality. A handful of institutions have required reviewers to consider individual contributions rather than lists of publications, and the shift has not been easy. Reviewers should be admonished for Googling individuals’ h-indices and citation lists, for example. Perseverance and self-reflection are essential.

Here is the Nature piece by Alan Finkel, via Lama.

Liu Cixin on American vs. Chinese science fiction

Presently — faced with the immaturity of Chinese sci-fi — everyone in our sci-fi community is envious of the adult sci-fi readership in the US, and see it as a sign of maturity in sci-fi literature. But one must know that senility comes after maturity, and death comes after senility. The prosperity of US sci-fi is largely a result of the prosperity of its movie and TV industries, and these sci-fi movies and TV shows are but a stylistic extension of the “golden age” (sci-fi). Contemporary sci-fi literature itself in US is already deep in twilight — full of works applying complex techniques to express dense metaphors, completely devoid of the youthful energy of the “golden age” (sci-fi); and many magnum opuses in recent years already have an air of death about them. Americans under 25 these days basically don’t read sci-fi; I don’t see what’s to be envied about that.

And this:

But to look at it in another way, sci-fi literature is by its very nature immature — because it shows humanity in its childhood, filled with curiosity and fear for the vast and profound universe, as well as the urge to explore it. In the face of such a universe, human science and philosophy are very immature, and sci-fi is the only literary form available to express our scientific and philosophical immaturities; so it’s no surprise that sci-fi is filled with immaturity. When human science is developed to the furthest extent and everything in the universe is discovered down to its minutia, that will be the day sci-fi dies.

Here is the entire Reddit thread, via Benjamin Lyons.

Unicorns Found!

Dr. Jorge Pérez, an evolutionary biologist from the University of La Paz, and several companions, were exploring the Andes Mountains when they found a small valley, with no other animals or humans. Pérez noticed that the valley had what appeared to be a natural fountain, surrounded by two peaks of rock and silver snow.

Pérez and the others then ventured further into the valley. “By the time we reached the top of one peak, the water looked blue, with some crystals on top,” said Pérez.

Pérez and his friends were astonished to see the unicorn herd. These creatures could be seen from the air without having to move too much to see them – they were so close they could touch their horns.

While examining these bizarre creatures the scientists discovered that the creatures also spoke some fairly regular English. Pérez stated, “We can see, for example, that they have a common ‘language,’ something like a dialect or dialectic.”

Dr. Pérez believes that the unicorns may have originated in Argentina, where the animals were believed to be descendants of a lost race of people who lived there before the arrival of humans in those parts of South America.

While their origins are still unclear, some believe that perhaps the creatures were created when a human and a unicorn met each other in a time before human civilization. According to Pérez, “In South America, such incidents seem to be quite common.”

However, Pérez also pointed out that it is likely that the only way of knowing for sure if unicorns are indeed the descendants of a lost alien race is through DNA. “But they seem to be able to communicate in English quite well, which I believe is a sign of evolution, or at least a change in social organization,” said the scientist.

Click here for the rest of the story.

Small teams vs. large teams in science

Here we analyse more than 65 million papers, patents and software products that span the period 1954–2014, and demonstrate that across this period smaller teams have tended to disrupt science and technology with new ideas and opportunities, whereas larger teams have tended to develop existing ones.

That is from a new Nature paper by Lingfei Wu, Dashun Wang, and James A. Evans.  Here is the NYT write-up by Benedict Carey.

Will insects go extinct?

No, probably not, no matter what you might have read or seen on Twitter.  The underlying paper is “Worldwide decline of the entomofauna: A review of its drivers.”  Here is a tweet thread by Alex Wild on the paper, here is one bit:

They make a great deal of local extinctions as a sort of proxy for global extinctions. That’s pretty dicey. I mean, bison are locally extinct here in my Austin neighborhood. But their numbers are recovering elsewhere.

They used 73 studies done on different taxa in different places. Those studies must represent tens of thousands of person-hours. Gargantuan. But the input studies weren’t designed for global assessment.

The paper itself has strong evidence on the severe pressure on butterflies and bees, and furthermore the general encroachment of humans on the natural environment probably is going to diminish species numbers and biodiversity, for insects too.  At the same time, the remaining species will adapt and evolve to meet the new potential habitats, with many kinds of insects having an easier time adapting than say gorillas.

The paper has some quite non-dramatic sentences such as: “Studies on ant populations and trends are lacking except for a few invasive species.”  And: “A single long-term study on grasshoppers and crickets is available…”

So I don’t quite see how the authors arrive at: “The conclusion is clear: unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades.”  Bryan Caplan, bet away!

Buy (or Rent) Coal! The Coasean Climate Change Policy

Since climate change and what to do about it are in the news it’s time to re-up an underrated idea, buy coal! Carbon taxes increase the price of carbon and induce economic and technological substitution towards lower-carbon sources of fuel in the countries that adopt them. As carbon-tax countries reduce fuel use, however, non carbon-tax countries see the price of their fuel decline. Thus, unless all countries join the tax-coalition, there is leakage. Supply-side policies are an alternative to demand supply policies. The United States, for example, could buy out and close coal mines, including giving the workers substantial retirement/reallocation bonuses, thus reducing the world supply of coal which is still the largest source of C02 emissions.

You can get rich by hitting an oil gusher, but coal is relatively expensive to mine and to transport. Thus, it’s relatively cheap to buy out coal mines because you aren’t buying the coal, you’re buying the right to leave the coal in the ground. Cutting the supply of coal raises its price which will increase the quantity supplied in other countries. Thus, there is the potential for supply leakage as well as demand leakage. It’s probably easier to use more coal when the price of coal falls (electricity, for example, can be generated in a variety of ways) than it is to mine more coal when the price rises. In other words, the elasticity of the demand for coal is greater than the elasticity of supply so supply leakage is probably less than demand leakage. Furthermore, supply leakage can be handled by buying out supply in the non-coalition countries. As Noah Smith pointed out with the graph at right (data) US CO2 emissions are actually falling while the rest of the world keeps rising (as they catch up in per-capita terms) so addressing the CO2 emissions problem requires bringing countries like China and India on board.

Coal use in China is very high and increasing. India has been canceling coal plants as solar becomes cheaper but coal is still by far the largest source of power in India. Thus, there is plenty of opportunity to buy out, high-cost coal mines in China and India.

It might seem odd to buy Chinese and Indian coal mines but we buy Chinese and Indian labor, why not a coal mine? Moreover, it’s important to understand that the policy is to buy only up to the point that it benefits both parties. Buying coal isn’t foreign aid, it’s a pollution reduction plan just like a carbon tax or R&D investment and because we can buy barely-profitable coal mines and avoid the problem of leakage this is a low-cost method to reduce CO2 emissions.

Collier and Venables worry that foreign voters won’t like foreign investors buying up coal mines, although foreign investment is hardly uncommon and foreigners do protect rainforests by buying the right to cut them down. In any case, Collier and Venables suggest a cap-extract and trade program. Under cap-extract there is a cap on global extractions of carbon (not use) but rights to extract can be traded. Since it’s more valuable to extract say oil than coal what this would mean is that payments would flow from mostly developed countries to developing countries which makes it clear that we are all in the boat together.

Even without a cap-extract and trade program, however, there are other factors that make buying coal attractive to people in selling countries, namely coal is killing them even putting aside the dangers of climate change.

NYTimes: Burning coal has the worst health impact of any source of air pollution in China and caused 366,000 premature deaths in 2013, Chinese and American researchers said on Thursday.

Coal is responsible for about 40 percent of the deadly fine particulate matter known as PM 2.5 in China’s atmosphere, according to a study the researchers released in Beijing.

India’s air quality is even worse than China’s and is responsible for some 1.2 million early deaths annually. A 25% cut in pollution in India could increase life-expectancy by 1.3 years and in some highly polluted cities such as Delhi by 2.8 years. Not all pollution comes from coal but a substantial amount does.

Buyers might worry that a foreign government will take their money and later renege on the deal. There are lots of ways to deal with this problem–turn the coal fields into a national park, for example, or develop them for housing. But let’s turn a problem into a solution. Instead of buying coal, we could rent it. In other words, buy the right to delay mining the coal for say 10 years. Given the rate of improvement in solar, many coal plants will be uneconomic in 10 years and given the rate of improvement in living standards and the consequent increased demand for clean air, many coal plants in India and China could well be unpolitical in 10 years. Thus, it is true that some solutions are naturally in the offing, but for exactly this reason some coal plants are going to be working extra hours in the next decade to squeeze out what profit they can while they still can. We can avoid this last push of CO2 into the atmosphere by buying up the right to extract and holding it for a decade.

A program to leave coal in the ground could easily pay for itself in lives saved and climate stabilized.

Paul Romer’s advice for the World Bank

First, outsource the bank’s research upon which it depends for identifying problems and proposing solutions. Diplomacy and science cannot both thrive under the same roof. One consequence of the bank’s commitment to diplomacy is its necessary embrace of the helpful ambiguity that makes it possible for multilateral institutions to allow “Chinese Taipei” compete in the Olympic Games without “Taiwan, China” having a seat in the UN. Dispassionate examination makes clear that what the bank does to maintain conformity on the diplomatic front is not compatible with scientific research.

All that matter in science are the facts. When complex political sensitivities are allowed to influence research by stifling open disagreement, it ceases to be scientific. For good reasons, the bank’s shareholders have chosen to protect its diplomatic function, at the expense of its research.

Outsourcing research would be a better, more efficient way for the bank to establish the facts needed to do its job. This would also be an investment in the universities that make the discoveries that drive human progress.

Here is the full piece.  What do you all think?