The unpredictability of “cumulative advantage”

I suppose this article from the NYT will be locked away behind a subscription soon, but Duncan J. Watts describes his team’s experiment and suggests that it’s never possible to predict swings in aggregate behaviour (e.g. how popular something is) beforehand simply because “cumulative advantage” is inherently unpredictable.

The reason is that when people tend to like what other people like, differences in popularity are subject to what is called “cumulative advantage,” or the “rich get richer” effect. This means that if one object happens to be slightly more popular than another at just the right point, it will tend to become more popular still. As a result, even tiny, random fluctuations can blow up, generating potentially enormous long-run differences among even indistinguishable competitors — a phenomenon that is similar in some ways to the famous “butterfly effect” from chaos theory. Thus, if history were to be somehow rerun many times, seemingly identical universes with the same set of competitors and the same overall market tastes would quickly generate different winners: Madonna would have been popular in this world, but in some other version of history, she would be a nobody, and someone we have never heard of would be in her place.


Because the long-run success of a song depends so sensitively on the decisions of a few early-arriving individuals, whose choices are subsequently amplified and eventually locked in by the cumulative-advantage process, and because the particular individuals who play this important role are chosen randomly and may make different decisions from one moment to the next, the resulting unpredictability is inherent to the nature of the market. It cannot be eliminated either by accumulating more information — about people or songs — or by developing fancier prediction algorithms, any more than you can repeatedly roll sixes no matter how carefully you try to throw the die.

Some will claim that there are underlying causes responsible for swings in consumption, but it’s always easy to come up with an explanation for something after it has happened (c.f. Snowden’s “retrospective coherence”)

So the writer asserts that at best, expert analyses are only relevant at that particular point in time, and should be treated with skepticism.

Read full article: NYT – Is Justin Timberlake a Product of Cumulative Advantage?

(From Overcoming Bias)

Taiji Kozaki – motion picture engineer & steam deliverer

(from PingMag)

With his Taisho-era film projector, formal Western costume and top hat, Taiji Kozaki looks like he just stepped out of cinema’s early past:

I project old animations in cinemas using a manual motion picture projector while reading out the dialogues and narratives according to the story. Motion picture was popular mainly during Meiji, Taisho, and the early Showa period – but it has practically disappeared now.

Read more: PingMag – A Motion Picture Engineer From A Distant Past

This modern day “motion picture engineer” also offers a “steam delivery” service, making tea at client-defined locations.

The past and future of hedgehogs and foxes

Tetlock (see earlier post) spurred me to track down a copy of Isaiah Berlin’s Russian Thinkers so I could zap a copy of “The Fox and The Hedgehog”.

The bulk of the essay examines Tolstoy’s particular philosophy of history, explains why it is self-contradictory and shows how that peculiar dilemma plays out in War and Peace. The definitions of the fox and the hedgehog are dealt with swiftly in the first page.

Berlin asserts that Tolstoy (at least while he was writing War and Peace) saw history as a fox, but wanted desperately to have a hedgehog’s explanation for history. Before postmodernism caught on, Tolstoy allegedly recognised that historians’ accounts of history were severely lacking because they privileged political interpretations of events and attributed success and failure to the actions of “great men” — politicians, generals etc — or to abstract ideas like “power” and zeitgeist. He saw that history, constructed out of the actions of all individuals, was unfathomably diverse. Berlin observes that the best parts of War and Peace consist of Tolstoy’s depictions of his individual characters. However, this did not stop Tolstoy from seeking some kind of unifying concept that would explain all of history, mostly by tearing down all the other grand pseudo-scientific theories of history e.g. historical dialectism.

Somewhat romantically in my opinion, Berlin sees this as some kind of deep inner struggle for truth. But Tolstoy never managed to articulate a coherent positive theory of his own it seems. Perhaps there isn’t one. The closest you might get is when:

something is perceived; there is a vision, or at least a glimpse, a moment of revelation which in some sense explains and reconciles, a theodicy, a justification of what exists and happens, as well as its elucidation.


What made the hedgehog/fox concept last? I thought the essay was almost a century old, but I was mistaken. Berlin wrote “The Hedgehog and the Fox” only recently in 1953. So is it just the momentum of academics and management gurus? Or is there something innately universal or timeless about that concept?

To what extent is the longevity of an idea tied to its media? Ideas need media (video formats, image files, books etc) to propagate. If ideas are viruses, media are the vectors. How do you preserve ideas?

Libraries and museums, though culturally significant now, don’t seem to work well in the very long term. For example, they’re susceptible to fire and, by virtue of the fact that they are in cities, vulnerable to sacking and destruction (e.g. the fabled Library of Alexandria, the National Museum of Iraq in more recent times). That’s not to say that we shouldn’t have them. These institutions inspire new works, new expressions of ideas. But that still leaves us with the problem of how to store cultural artifacts.

Most preservation appears to be serendipitous, like how you can only see footage of old Singapore in commercial work: Saint Jack (see earlier post), Ring of Fury, SBC drama serials etc. There was no deliberate decision to preserve. In a similar vein, I recall researchers discussing how porn distribution might hold important lessons for preserving digital art. Not so surprising when you consider that large numbers of items that that we now consider “historically significant” were uncovered from rubbish dumps like those at Oxyrhynchus. Makes you wonder what archaeologists hundreds of years from now will conclude from our cultural detritus.

TED – videos of ideas and lectures online

TED (Technology.Entertainment.Design), a well-known ideas conference, has made videos of its 2007 talks available online and downloadable into your media device of choice. Sponsored by BMW, high profile and polished, which somehow makes me wonder how much of the content is hollow posturing and how much is actually worth listening to. Wish I had time to find out.


Quick Note: House of Meetings

Although the blurb plays up the love triangle formed by the unnamed narrator, his brother Lev and the target of their love Zoya, it’s really about the brothers’ relationship over the decades.

Amis tries a bit too hard to express his own ideas about Russia through a well-read and world-weary narrator’s memoir allegedly addressed to his step-daughter (whose voice is expressed only in the footnotes explaining Russian names). The narrator, Lev, Zoya — their experiences sometimes appear to be just launching pads for wry, bleak ruminations on Russia’s sorrow-soaked self-destruction.

Philip Tetlock: Foxes and Hedgehogs

Tetlock also found that specialists are not significantly more reliable than non-specialists in guessing what is going to happen in the region they study. Knowing a little might make someone a more reliable forecaster, but Tetlock found that knowing a lot can actually make a person less reliable. “We reach the point of diminishing marginal predictive returns for knowledge disconcertingly quickly,” he reports. “In this age of academic hyperspecialization, there is no reason for supposing that contributors to top journals — distinguished political scientists, area study specialists, economists, and so on — are any better than journalists or attentive readers of the New York Times in ‘reading’ emerging situations.” And the more famous the forecaster the more overblown the forecasts. “Experts in demand,” Tetlock says, “were more overconfident than their colleagues who eked out existences far from the limelight.”

From a review of his book in The New Yorker.

He gave a presentation to the Long Now Foundation earlier this year. There’s a summary, but there’re still interesting points that weren’t included. Consider listening to the mp3 recording.

Tetlock is referencing Isaiah Berlin’s essay “The Hedgehog and the Fox“. A friend once mentioned this to me some time ago in a conversation about HR practices and talent attraction. That conversation sort of dissipated (as casual banter is wont to do) a little after we concluded that although our employers might say they wanted foxes, they were really rewarding hedgehogs.

Speaking of HR, Mr Wang’s post on how the civil service allegedly evaluates performance and potential has been attracting lots of attention. If you ignore the flaming, there’re some good contributions and anecdotes in the comments section.