Pages in this blog

Thursday, November 2, 2023

What economic growth and statistical semantics tell us about the structure of the world

Bumping this to the top of the queue on general principle, and because it takes a very abstract view of economic development, which is front and center in Tyler Cowen's current conversation with Stephen Jennings, who is a developer working Kenya.


New working paper. Title above. Download at:
Abstract, contents, and first section below.



Abstract: The metaphysical structure of the world, as opposed to its physical structure, resides in the relationship between our cognitive capacities and the world itself. Because the world itself is “lumpy”, rather than “smooth” (as developed herein, but akin to “simple” vs. complex”), it is learnable and hence livable. Machine learning AI engines, such as GPT-3, are able to approximate the semantic structure of language, to the extent that that structure can be modeled in a high-dimensional space. That structure ultimately depends on the fact that the world is lumpy. It is the lumpiness that is captured in the statistics. Similarly, I argue, the American economy has entered a period of stagnation because the world is lumpy. In such a world good “ideas” become more and more difficult to find. Stagnation then reflects the increasing costs the learning required to develop economically useful ideas.

Contents

Wending our way in a complex world 2
World, mind, and learnability: On the metaphysical structure of the cosmos 5
Stagnation, Redux: Like diamonds, good ideas are not evenly distributed 10
The complex universe: Further reading 18

Wending our way in a complex world

This paper is based on two very different posts that I’ve written in the last month. One of them takes the statistical semantics of AI engines like GPT-3 as its starting point: “World, mind, and learnability: On the metaphysical structure of the cosmos” (revised considerably for this paper). The other is about economic growth and stagnation: “Stagnation, Redux: Like diamonds, good ideas are not evenly distributed”.

These two very different papers nonetheless share both substance and method. Methodologically, both argue that the situation we observe is intelligible if we assume that the world is structured in a certain way. Their core substance is about that structure: the world must be “lumpy” – a notion I discuss on pages 5 ff. Because the world is lumpy we can learn about it, live in it, talk about it, and write about it. By contrast, a “smooth” world would be unintelligible and hence unlivable. The exhaustive statistical analysis of a large body of text is, in effect, able to recover that structural lumpiness as reflected in language and use it to produce new texts.

However, because the world is lumpy, we begin by learning and benefiting from things close to hand. When those resources have been exhausted we and must travel deeper into the world, expending more and more effort to extract economic benefit. Our current economic stagnation reflects the increasing cost of learning more about the world. A smooth world would no doubt be more convenient, for there would be economic benefit at every turn, either that or economic disaster. That is, if the world were smooth, we wouldn’t be here.

That, I know, this talk of smoothness and lumpiness is very abstract and “featureless”. But then could a resonance between such disparate phenomena as statistical semantics and economic stagnation but be abstract? I’ll provide more substance later in this paper, some diagrams, and some arguments. But first I want to suggest that what I’ve been calling lumpiness is what Ilya Prigogine and many others have called complexity.

Our complex world

Some years ago David Hays and I wondered why natural selection leads to complexity [1]. We argued that, over the long run, natural selection favors organisms with increased ability to process information, and that ability yields benefits in a complex universe. But what did we mean by that, a complex universe? Here is what we said:
It is easy enough to assert that the universe is essentially complex, but what does that assertion mean? Biology is certainly accustomed to complexity. Biomolecules consist of many atoms arranged in complex configurations; organisms consist of complex arrangements of cells and tissues; ecosystems have complex pathways of dependency between organisms. These things, and more, are the complexity with which biology must deal. And yet such general examples have the wrong “feel;” they don't focus one's attention on what is essential. To use a metaphor, the complexity we have in mind is a complexity in the very fabric of the universe. That garments of complex design can be made of that fabric is interesting, but one can also make complex garments from simple fabrics. It is complexity in the fabric which we find essential.

We take as our touchstone the work of Ilya Prigogine, who won the Nobel prize for demonstrating that order can arise by accident (Prigogine and Stengers 1984; Prigogine 1980; Nicolis and Prigogine 1977). He showed that when certain kinds of thermodynamic systems get far from equilibrium order can arise spontaneously. These systems include, but are not limited to, living systems. In general, so-called dissipative systems are such that small fluctuations can be amplified to the point where they change the behavior of the system. These systems have very large numbers of parts and the spontaneous order they exhibit arises on the macroscopic temporal and spatial scales of the whole system rather than on the microscopic temporal and spatial scales of its very many component parts. Further, since these processes are irreversible, it follows that time is not simply an empty vessel in which things just happen. The passage of time, rather, is intrinsic to physical process.

We live in a world in which “evolutionary processes leading to diversification and increasing complexity” are intrinsic to the inanimate as well as the animate world (Nicolis and Prigogine 1977: 1; see also Prigogine and Stengers 1984: 297-298). That this complexity is a complexity inherent in the fabric of the universe is indicated in a passage where Prigogine (1980: xv) asserts “that living systems are far-from-equilibrium objects separated by instabilities from the world of equilibrium and that living organisms are necessarily ‘large,’ macroscopic objects requiring a coherent state of matter in order to produce the complex biomolecules that make the perpetuation of life possible.” Here Prigogine asserts that organisms are macroscopic objects, implicitly contrasting them with microscopic objects.
That is to say, the world has two regimes, the macroscopic and the microscopic, and they differ in more than size:
Prigogine has noted that the twentieth century introduction of physical constants such as the speed of light and Planck's constant has given an absolute magnitude to physical events (Prigogine and Stengers 1984: 217-218). If the world were entirely Newtonian, then a velocity of 400,000 meters per second would be essentially the same as a velocity of 200,000 meters per second. That is not the universe in which we live. Similarly, a Newtonian atom would be a miniature solar system; but a real atom is quite different from a miniature solar system.

Physical scale makes a difference. The physical laws which apply at the atomic scale, and smaller, are not the same as those which apply to relatively large objects. That the pattern of physical law should change with scale, that is a complexity inherent in the fabric of the universe, that is a complexity which does not exist in a Newtonian universe. At the molecular level life is subject to the quantum mechanical laws of the micro-universe. But multi-celled organisms are large enough that, considered as homogeneous physical bodies, they exist in the macroscopic world of Newtonian mechanics. Life thus straddles a complexity which inheres in the very structure of the universe.
That, then, is at the heart of what I mean when I talk of the world as being lumpy rather than smooth. The world is complex, not in the sense that it has many parts intricately arranged, but that, over the long run, the interplay of physical laws tends toward proliferation and diversity of objects. Long term evolutionary dynamics are inherent in the structure of physical law.

With that as background, we are just about ready to plunge into the argument. But I want to address one last issue.

What does this have to do with metaphysics?

Metaphysics as a branch of philosophy, and this paper does not look like philosophy as it is currently taught in colleges and universities, whether in the Anglo-American analytic tradition or the more discursive and literary Continental tradition. Those are specialized academic disciplines. This paper is something else. Speculative, yes, but speculation is search of broad understanding.

Here and there a variety of thinkers have suggested that there is a lot of philosophy around and about that’s philosophical in an older more synthetic sense of the word. There was a time – not all that long ago – when philosophers tried to synthesize human knowledge over a wide range of topics and make sense of the world as a whole. That enterprise was quite different from academic philosophy of whatever kind, which is much narrower in scope.

Eric Schliesser, for example, has recently argued for synthetic philosophy [2]:
By ‘synthetic philosophy’ I mean a style of philosophy that brings together insights, knowledge, and arguments from the special sciences with the aim to offer a coherent account of complex systems and connect these to a wider culture or other philosophical projects (or both). Synthetic philosophy may, in turn, generate new research in the special sciences, a new science connected to the framework adopted in the synthetic philosophy, or new projects in philosophy. So, one useful way to conceive of synthetic philosophy is to discern in it the construction of a scientific image that may influence the development of the special sciences, philosophy, public policy, or the manifest image.
He is reviewing two books, From Bacteria to Bach and Back: The Evolution of Minds, by Daniel Dennett, and Other Minds: The Octopus and The Evolution of Intelligent Life, by Godfrey Smith. Both men are analytic philosophers who have published a variety of technical papers. But neither of those books is a work of technical analytic philosophy.

Rather, they are works of synthetic philosophy that bring together work from a wide variety of intellectually specialized sources, many of then in the various sciences, into a single intellectual framework. I think that many works written by academic specialists for a general audience are thus works of synthetic philosophy. Some other examples that come to mind: Jared Diamond, Guns, Germs, and Steel: The Fates of Human Societies; Steven Pinker, How the Mind Works; Steven Mithen, The Singing Neanderthals: The Origins of Music, Language, Mind and Body, and my own, Beethoven’s Anvil: Music in Mind and Culture.

My purpose in this working paper isn’t that grand. I am not proposing a synthesis that embraces both the economics of growth and computational semantics. Rather, I am arguing that, considered at the proper level of abstraction, both of those disciplines encounter similar issues. It’s not that I think that these disciplines can be put to work solving one another’s problems but rather that both give us parallel and congruent insights into the nature of the world. Ultimately they are coping with the same thing, how we live in a complex world.

References

[1] William L. Benzon and David G. Hays, A Note on Why Natural Selection Leads to Complexity, Journal of Social and Biological Structures 13: 33-40, 1990, https://www.academia.edu/8488872/A_Note_on_Why_Natural_Selection_Leads_to_Complexity.

[2] Eric Schliesser, Synthetic Philosophy, Biology & Philosophy, Vol. 34: 19, 2019, https://doi.org/10.1007/s10539-019-9673-3.

No comments:

Post a Comment