Posts tagged with ideas

Neurons are designed with a lot of listeners (the dendrite) and just one talker (the axon terminal).
If we consider the brain as a robust piece of hardware, which can
learn across environments,
operate independently of the rest of the organisation of the superstructure,
and function even after sustaining physical damage,
maybe there’s a universal principle of good design here.

Neurons are designed with a lot of listeners (the dendrite) and just one talker (the axon terminal).

If we consider the brain as a robust piece of hardware, which can

  • learn across environments,
  • operate independently of the rest of the organisation of the superstructure,
  • and function even after sustaining physical damage,

maybe there’s a universal principle of good design here.


But there were also more profound features, which took me a long time even to notice, because they are so at odds with modern experience that neither New Guineans nor I could even articulate them. Each of us took some aspects of our lifestyle for granted and couldn’t conceive of an alternative.

Those other New Guinea features included the non-existence of “friendship” (associating with someone just because you like them), a much greater awareness of rare hazards, war as an omnipresent reality, morality in a world without judicial recourse, and a vital role of very old people. …

Many of my experiences in New Guinea have been intense—a sudden encounter at night with a wild man, the prolonged agony of a nearly-fatal boat accident, one broken little stick in the forest warning us that nomads might be about to catch us as trespassers …

Jared Diamond, The World Before Yesterday

via University of David

The Nielsen PRIZM groups people into 66 “demographic and geographic market segments” for the purpose of advertising to them.

Each of the segments has a nice description to go along with it. It’s the kind of story you want to hear as a marketer: it uses relatively in-depth knowledge of Americans, plus stereotypes or shallow summaries, to draw a character with enough roundness that you could pitch to him/her. That is, you could write copy or film a creative spot that you believe could speak to members of this cohesive segment.

As I read more deeply into the Nielsen-Claritas PRIZM, however, the 66 segments started to sound like perhaps they were generated by a simple formula. From their slideshow I learned that they divide the US population by:

  • affluence
  • population density
  • kids/no kids + age

Rather than use continuous on the implied cube (3 dimensions above), they lump various ranges together. They also lump the interaction terms unevenly—for example, (suburban & income) is lumped more finely and (urban & income) is lumped more coarsely. Specifically,

  • 4 totally -ordered levels of urbanity (measured by population density per zip code) urban  suburban  second city  town & rural
  • 14 levels of Affluence Groups (so they consider finer gradations of wealth & income within suburban and low-density zip codes and coarser income gradations in cities and second-cities)
  • Three life-stage categories, accommodating both those who do and don’t raise children at some point. {youngish && no kids, kids, oldish && no kids at home}.

    Younger folks (this is under-35’s or under-45 DINKs) are less graduated by affluence than families or older folks (over-55’s or over-45 DINKs).

    By the way, over-65’s are outside PRIZM’s marketing groups. I guess it’s assumed that they won’t buy big-ticket items or change their ways much unless the Monday lima-bean special becomes 25cents cheaper at Lida’s Diner than Bill’s Diner. Then you’ll see the entire community switch to Lida’s.

Like the MBTI, it assumes that: People fit in rectangles.

Unlike the MBTI, rather than using four sliding scales [0,1]⁴, the PRIZM uses discrete, totally ordered sets—something you could build with the letters and combn functions in R.

I started to wonder: is it really true that members of segment 26 are “urbane” and “love the nightlife” — even the empty-nesters and older homeowners of the segment? Is there really a “laid-back atmosphere” to segment 25? Or are these merely colourful papier-mâché rudely draped over a box?

Mostly, of course, I’m concerned with segment 31, the well-known Urban Achievers:

And proud we are of all of them.


When I look at a painting, I’m tempted to glance quickly and pass on. In order to appreciate a piece, I imagine the strokes and colour choices that make up the painting. I imagine myself painting the same thing. What would it have felt like to be inside Cy Twombly's hand while he painted Apollo 17? That gives me a better feeling of the art.

When I look at the Nielsen Prizm the same way — try to get inside the heads of its creators — I sense that they adopted the [0,1]⁸ rectangular structure simply because they’re not aware of alternatives. MBA’s do plenty of mathematics, but I’ve never seen any business mathematics cross over into CW-complexes, 3-tori, arborescences, or Lobachefskyan geometries. It could be that the people who designed the Prizm simply didn’t have anyone on their team who had heard of this stuff. All the quants were working on Wall Street rather than Madison Avenue. (Wacker Drive rather than Michigan Ave.)

The ribbon-farm guy (Venkatesh Rao) is a rocket scientist who crossed over into marketing, but so far I haven’t read enough of his stuff to say if he dove into algebraic geometry—it seems he did more functional analysis, optimisation / control theory, and differential geometry. Which is what I would expect rocket science consists of.

I will admit that the PRIZM’s use of two “matrix” presentations with colour-coding, pictures, defined ranges, and toss-away combinations is quite clear. Probably works better than when I tell clients “Just picture a 5-dimensional manifold, I won’t say the norm because I think it’s spaced differently in the center than the edges—and let’s not get into the interaction terms yet”. But—the bones of their model are really just [0,1]³. They’ve dressed it up and they’ve done more than that (segmenting and dropping). But a cube is the underlying architecture.

Is the Prizm simple or oversimplified? I feel it’s the latter. Not that I object to mathematical models of behaviour, emotions, or any human thing—but the hypercube metaphor just doesn’t fit my presumption of the shape of the space.

  • Does consumer space have 8 corners to it?
  • What’s the best interpretation of “distance” in the consumer space?
  • Do all of the lines really cross at right angles, in a hyper-grid? Was that supposed to be implied?


I don’t want to carp about somebody else’s work without at least offering constructive criticism. What are some potentially better ways to think about the space of all consumers—potential buyers of houses, cars, vacations, DVD’s, washers, ‘n’all that?

Mathworld’s picture of a few topological objects gives one starting point:

One thing I noticed pretty quickly: you remember playing Star Fox battle mode? Or any video game where there is a lower-right thumbnail of you on a limited square map—such that when you go leftwards off the map you appear on the right, and when you go upwards off the map you appear on the bottom? As a kid I thought I was flying on the surface of a planet, but in fact it was the surface of a torus. (Why? If you go up to the top of the North Pole you don’t come out again at the South Pole. See the picture of the sphere with B ≠ C, i.e. N ≠ S.)

In other words, a torus (donut) is the product of a_loop × a_loop. Whereas a sphere (ball) is the product of a_loop (east/west) × a_line_segment (north/south).


Following from this short lesson in topology, one alternative to multiplying only “linear” dimensions of characteristic attributes would be to multiply lines with loops. For example a_loop × a_loop × a_line_segment. I’m not sure what the name for that shape is, but you can imagine it — like a cylindrical torus. And it’s logically possible that there are two circle-like dimensions in marketing. Something like, as politics goes further and further left, it starts to resemble the far right more than the middle. But relevant to marketing.

A second alternative then might be to consider, like in the image above, the endpoints of some line segments from the 3 dimensions of Nielsen. What if some of them were identified rather than left distinct? What kind of shapes could you create with that and would that resemble the consumer space more than a rectangle?

Some other ideas of things to question:

  • How do angles meet up? (inner product)
  • How do distances work? (norms)
  • Look through an algebraic geometry book, or Solid Shape. Are there any shapes—umbilics, furrows, biflecnodes, dimples, trumpets—that have an analogue in the space of all consumers?
  • Is backwards just the opposite of forwards? Or does that wrongly assume commutativity?

I don’t know if that would result in a better model. I don’t know if thinking about things this way would reduce wasteful ad spending. I don’t have data to test these ideas on. I just wanted to share this thought.

I had nothing but ideas.

O.K., they weren’t strictly mine, in the sense that these ideas were acquired, arranged, styled, photographed, published and distributed by entities bearing no relation to me whatsoever.

The last time I was reading the Zhoangdze, I got sidetracked by footnotes about the following 白馬論:

  • "A white horse is not a horse."

This is apparently attributable to Gongsun Long 公孙龙, a Chinese philosopher of the 3rd century B.C. = Era of Warring States 战国时代. How could such a wack philosopher be worth dignifying with a mention in the  庄子?

Juang Tzu

I got my answer from page 40 of James Gleick’s The Information. Like most ancient debates, this all relates back to Bill Clinton and Monica Lewinsky.

  • Big Bill Clinton, Rhodes Scholar: “That depends what the meaning of the word is, is.”

Too true, my man.

As Bill Thurston pointed out, students of mathematics regularly use the = symbol when it’s not appropriate (maybe an or or or set comprehension is what’s needed) just because it’s the only “connecting word” they know. But the meaning of “is” is too multifarious to always translate to the = symbol. For more tools of how to think about what exactly we’re saying with “is”, check out two papers I’ve linked on this site: Barry Mazur's When is a thing equal to some other thing? and John Baez + James Dolan’s From Finite Sets to Feynman Diagrams.

You might have thought I would stoop to a seductive pic of Ms Lewinsky, but I'm too good for that. Here's an ancient map of China, Warring States period.

Back to the ancient Chinese stuff. What 公孫龍 was trying to say, was that

  • "white horse" “horse”

in the sense of the = sign. The = sign means you can freely substitute one thing for another—to the point of ridiculousness if you wish—without distorting the truth value. But using Gleick’s example,

  • "Lana doesn’t like white horses” does not mean “Lana doesn’t like horses”

Really "white horse" ⊂ "horse", a white horse is a kind of horse, but that means in an object-oriented programming sense we’re talking about class inheritance, not ===.

Now afore you go runnin afeart that the English | Chinese language is being shoehorned into mathematical symbology, read a couple sentences of Quine. In this case a bit of set theory and technical statements like “The set of all referents satisfying the criteria X also satisfy the criteria Y”, and thinking about alternatives to = like  and , actually makes our English-language thinking clearer.


UPDATE: Jeremy Tran explains that:

[As] I understand it. For “is ≡”, we use the phrase 一樣, while for “is ⊂”, we have 一種. These two concepts are relatively distinct from each other. The ‘proper’ translations for the two are “the same” and “a type of”, respectively. But often, those two are translated into English simply as “is”, which can lead to issues.

My Chinese isn’t exactly the best, so hopefully I haven’t made any big mistakes. But this is the gist of it. :D

Somebody can kill you, at any time.

[T]he Efficient Markets Hypothesis [is] in contention for one of the strongest hypotheses in the whole of the social sciences.

Strictly speaking the EMH is false, but in spirit it is profoundly true. Besides, science concerns seeking the best hypothesis, and until a flawed hypothesis is replaced by a better hypothesis, criticism is of limited value.

Martin Sewell

Um … the criticism might not be useful to science, but knowing that the EMH is false is certainly useful to market participants.

The Kelly Rule for optimal bet sizing says to leverage your bet in geometric proportion to your confidence. So a small reduction in confidence means a big reduction in (optimal) leverage.

I could also wheedle about how obvious modifications of the EMH are more correct than strong EMH, but I won’t. My main thought on this quote is that Sewell has effectively redefined “truth” so that his viewpoint is unfalsifiable. (What example could I cite to demonstrate that EMH is not “profoundly true in spirit”?) On the other hand, it would be naive of me to think that esthetics and organa are not driving the engine of any kind of theory—be it economics, physics, or Foucault.

Anyway … despite the fervour of the abstract (from which I’m quoting), Martin Sewell’s History of the Efficient Markets Hypothesis is an informative read. 


While science rightly uses empirical evidence (facts) as the ultimate arbiter of truth, those who experiment and analyse field data usually only credit or discredit ideas / frameworks that some theorist has previously invented.

Science: We finally figured out that you could separate fact from superstition by a completely radical method: observation. You can try things, measure them, and see how they work! Bitches.

Tagline. Science: We finally figured out that you could separate fact from superstition by a completely radical method: observation. You can try things, measure them, and see how they work!

Hence the name “theory-killers” for experimental physicists.


Where do these theories come from, though? My own experience and my observations of others lead me to believe that an economic theorist’s deep creative centre is informed, flavoured, shaped, and sullied by her own personal experiences, biases, stereotypes, and assumptions about what’s normal. If you talk to people who have deeply integrated into their psyche concepts like “opportunity cost”, “rationality”, “search”, “strategy”, “information”, “evolution”, “optimisation”, and so on, and you disagree with this statement, please tell me.

(For example: a professor of game theory told me that he cannot fathom the motivations of a suicide bomber. He can’t fathom them, so he can’t model them, so we have no theory to predict and curtail their bombing behaviour.

Example 2: Do you think Daniel Ellsberg started running psychological experiments at random until he stumbled upon his famous "Ellsberg Paradox"? No, he had the idea in his head that these two kinds of “uniform distribution” should be different—perhaps getting the idea from Keynes or Frank Knight—and
 then tested the idea.)

Since there’s a "lone genius" limit on novel* economic theories, a finite upper bound follows on how much fact-checking can improve a theory’s soul. Although one can certainly benefit from pulling on threads, reading monographs, looking at data tables and so on, ultimately I believe deep insights come from the same brain process that generates the fallacy of lack-of-imagination (argumentum ad ignorantiam). Just as people form judgments by the “Does this fit with what can I imagine” test, so too—says I—do economic theories rise from the same murky pit. Personal experiences where we’ve taken in reams of high-dimensional streaming data (like at work) feed this imaginative capacity, such that we can run and assess counterfactual dramas in our heads (sort of like a Monte Carlo). "What if the vendor had said this to my boss? Nah, she wouldn’t have reacted that way. Not like her." There are some biologists who say that our brains have an especial capability to think through such human dramas. (And in writing that sentence I used the same often fallacious imaginative faculty.) The imaginative faculty is abused by cheap stereotypes—

Ideas can be checked against experiences and personal symbols much more easily than against a tome of facts. Since theoretical creativity proceeds in inspirational flashes and needs to run verificational checks at the speed of imagination, only the checks that can be done very quickly influence the creative process.

* Of course most theories derive from the joining of ideas from the existing literature. But those aren’t “novel” ideas.

It’s my conviction, therefore, that theoretical economists would come up with better theories if they spent more time in “the real world” and less time thinking about isomorphisms.


The problem is more acute in economics than in physics, because economic theories are much harder to kill (so many alternative explanations / dismissals one can retreat to) — which shifts some of the burden of correctness to the theorists. If you know that

  1. a compelling idea (like “Those who spend other people’s money will be wasteful”) will be hard to falsify;
  2. it will spread memetically through influential minds;
  3. it’s important to get this right, or else the former USSR and Latin American countries (𝓞 1 billion people) will be screwed over by your idea

then you would be quite reasonable in polishing & perfecting a theory—working to cleanse yourself of biases and myopia, asking yourself if what you’re writing is really quite true, what are the underlying assumptions, and so on.

The problem is also more important for economic theorists to address because those who theorise about the human mind have, erm, direct access to the thing they’re theorising about.


The difficulty of killing an economic theory has been discussed much elsewhere:

and if you read the things I read, you’ve probably had similar thoughts as:

  • "Really? It took this long for ‘neoindustrial’ ideas like ‘The economics of serfdom differ from the economics of a modern web programmer’ to become acceptable?" And neo-industrial uses a totally neoclassical approach but just in a meta context—rational response to the incentives that come with a social framework, or perhaps game theory rationally optimising evolution rather than individuals.
  • "Really? People think you can just use a probability distribution to model a person’s or a firm’s thought-process?"
  • "Really? We just shrug off counterevidence to the theories by saying they’re only models?”
  • "Really? Real numbers and Lagrangians are underlying all of this?”
  • "Really? It’s so controversial that utility is derived from relative and not absolute wealth?”

and many others. Point being, if you are educated on this stuff, then I’m sure you can see how the Slutzsky decomposition is a compelling advance in “research technology”, but can’t carry over as-is to the ultimate subject of interest, which is human behaviour and feelings.


Am I just carping? A bit, but I also can propose something like a solution. If those who give out grants for economic research could be convinced that

  • business experience
  • time spent in poor countries
  • experience in a variety of economic roles outside of academia

were important indicators of future relevancy and correctness of research—along with knowledge of a body of literature, knowledge of mathematical/statistical/experimental methods, consulting/political experience, and/or a Ph.D.—then up-and-coming economists would have the incentive to spend time in “the real world” and find out, in a personal way, what the people they theorise about go through.

Chen […] thinks that if your language has clear grammatical future tense marking […], then you and your fellow native speakers have a dramatically increased likelihood of exhibiting high rates of obesity, smoking, drinking, debt, and poor pension provision.

And conversely, if your language uses present-tense forms to express future time reference […], you and your fellow speakers are strikingly more likely to have good financial planning for retirement and sensible health habits.

It is as if grammatical marking of the difference between the present and the future insulates you from seeing that the two are coterminous so you should plan ahead. Using present-tense forms for future time reference, on the other hand, encourages you to see that the future is just more of the present, and thus encourages you to put money in a 401(k).

Geoff Pullum


Newton came to be thought of as the first and greatest of the modern age of scientists, a rationalist, one who taught us to think on the lines of cold and untinctured reason.

I do not see him in this light. Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind which looked out on the visible and intellectual world with the same eyes as those who began to build our intellectual inheritance rather less than 10,000 years ago.
John Maynard Keynes, in 1942