Information, information, information

Yesterday my dear husband (@ruskin147) interviewed César Hidalgo (@cesifoti) about his new book for next week’s edition of Tech Tent (19 June) on the BBC World Service. I’m very excited about reading this book. I’ve long been a fan of The Atlas of Complexity, on which Prof Hidalgo has worked. Besides, here is the overlap of information, complexity and spontaneous order, computing and economics – what’s not to like?

Prof Hidalgo in the BBC's New Broadcasting House yesterday

Prof Hidalgo in the BBC’s New Broadcasting House yesterday

Economists will naturally think immediately of Hayek’s famous 1945 article, The Use of Knowledge In Society, which is cited in the introduction here. Although information asymmetries are huge in many areas of economics now, I still don’t think we work out often enough or in sufficient detail the implications of information mattering so much. For years – since the mid-90s – I’ve been saying to colleagues that information technology is a profoundly important deal for economic organisation and even now too often get the reaction, well we know how to handle a transaction cost reduction in our models so what’s the big deal?

Anyway, I’m immensely looking forward to reading this and will report back.

[amazon_image id=”0241003555″ link=”true” target=”_blank” size=”medium” ]Why Information Grows: The Evolution of Order, from Atoms to Economies[/amazon_image]

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Grass roots

There’s an interesting evaluation of Jane Jacobs in The Architectural Review, arguing that her fabulous book  misses the real target in attacking ‘planners’ instead of developers, and discounting the scope for state involvement. This made conservatives fond of her, essay author Sharon Zukin argues. But it concludes warmly: “Jacobs’s challenge to maintain the authenticity of urban life still confronts the fear of difference and the hubris of modernising ambition. At a time in which local shopping streets are the target of attacks against a broader alienation, we urgently need to connect her concern with economic development and urban design to our unsettled social condition.”

[amazon_image id=”067974195X” link=”true” target=”_blank” size=”medium” ]The Death and Life of Great American Cities (Vintage)[/amazon_image]

The essay cites the famous ‘sidewalk ballet’ in the second chapter in :

“Under the seeming disorder of the old city, wherever the old city is working successfully, is a marvelous order for maintaining the safety of the streets and the freedom of the city. It is a complex order. Its essence is intricacy of sidewalk use, bringing with it a constant succession of eyes. This order is all composed of movement and change, and although it is life, not art, we may fancifully call it the art form of the city and liken it to the dance — not to a simple-minded precision dance with everyone kicking up at the same time, twirling in unison and bowing off en masse, but to an intricate ballet in which the individual dancers and ensembles all have distinctive parts which miraculously reinforce each other and compose an orderly whole. The ballet of the good city sidewalk never repeats itself from place to place, and in any once place is always replete with new improvisations.”

Echoes of course of that other grassroots philosopher Adam Smith. Not only: “It is not from the benevolence of the butcher, the brewer, or the baker, that we expect our dinner, but from their regard to their own interest,” from , but also this from :

“The man of system…is apt to be very wise in his own conceit; and is often so enamoured with the supposed beauty of his own ideal plan of government, that he cannot suffer the smallest deviation from any part of it… He seems to imagine that he can arrange the different members of a great society with as much ease as the hand arranges the different pieces upon a chess-board. He does not consider that in the great chess-board of human society, every single piece has a principle of motion of its own, altogether different from that which the legislature might choose to impress upon it.”

  [amazon_image id=”0143105922″ link=”true” target=”_blank” size=”medium” ]The Theory of Moral Sentiments (Penguin Classics)[/amazon_image]   [amazon_image id=”B00JVST6CA” link=”true” target=”_blank” size=”medium” ]The Wealth of Nations[/amazon_image]

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The El Farol problem goes digital

I saw this tweet and it immediately reminded me of Brian Arthur’s El Farol equilibrium story.

AdamRFisher
Please develop an app that simulates Waze recommendations to assess which routes will open up based on everybody else follow Waze.
13/05/2015 07:12

For those who don’t know it, El Farol is a bar in Santa Fe, where Arthur is based. It has great Irish music but the problem is that it’s no fun if the bar gets too crowded. What is the outcome in this situation where people are trying to choose based on beliefs about what others will choose? There is no ‘deductively rational’ solution to this choice problem. In his paper, Arthur writes: “If all believe few will go, all will go. But this would invalidate that belief. Similarly, if all believe most will go, nobody will go, invalidating that belief. Expectations will be forced to differ.” Simulating behaviour of 100 agents repeatedly shows that mean attendance at El Farol quickly converges to 60, but with large swings from period to period, and changing identity of those attending – it isn’t always the same 40 with a varying number of extras. “while the population of active predictors splits into this 60/40 average ratio, it keeps changing in membership forever. This is something like a forest whose contours do not change, but whose individual trees do. These results appear throughout the experiments, robust to changes in types of predictors created and in numbers assigned.”

The Waze problem looks similar. If you see congestion on your planned route, you’ll switch to an alternative – perhaps – for you also have to predict how many other people will switch too, and whether the initial congestion will stay or vanish if there are enough other users of similar apps.

Later work on El Farol found one game theoretic solution: individual agents adopt a mixed strategy, whereby each has a fixed probablility of choosing either El Farol or an alternative bar. Another is that after a period of learning, agents sort themselves into groups, those who always go and those who always stay home. But I don’t think these work for Waze-style congestion problems which are not repeated.

Indeed, real-time apps are surely creating more of these kinds of co-ordinated decision problems.

Brian Arthur’s book is a nice introduction to his work.

[amazon_image id=”B00SLUR9HI” link=”true” target=”_blank” size=”medium” ]Complexity and the Economy: Written by W. Brian Arthur, 2014 Edition, Publisher: Oxford University Press, USA [Hardcover][/amazon_image]

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Markets in stories

Yesterday I attended a very interesting conference, on Non-Equilibrium Social Science, which stands for making economics more realistic and interesting – looking at the economy in terms of non-linear dynamic systems. As ever at a good conference there were some great opportunities for conversation – and book recommendations. I came away with Marion Fourcade’s , and W.E.G.Salter’s , and William Hazlitt’s 1805 .

[amazon_image id=”0691148031″ link=”true” target=”_blank” size=”medium” ]Economists and Societies: Discipline and Profession in the United States, Britain, and France, 1890s to 1990s (Princeton Studies in Cultural Sociology)[/amazon_image]   [amazon_image id=”1144113512″ link=”true” target=”_blank” size=”medium” ]An Essay On the Principles of Human Action: Being an Argument in Favour of the Natural Disinterestedness of the Human Mind..[/amazon_image]

Also, after hearing him speak, David Tuckett’s . His argument was, in a nutshell: “Financial markets are markets in stories.” He classed as standard models both the rational choice and ‘behavioural’ approaches to decision making, because both assume there is an objective reality about which an optimum can in principle be known or calculated. Instead, Prof Tuckett argued, the decision problem is one of making any sense at all of how to act now on the basis of information now about an ontologically uncertain future. His answer is that we act on the basis of ‘conviction narratives’ which are collective interpretations of what today’s ‘facts’ (all based on our sense perceptions) mean for tomorrow. He described some empirical work looking at the stories that run in financial markets, as extracted from unstructured texts such as newswire reports, brokers’ notes and Bank of England reports.

[amazon_image id=”0230299857″ link=”true” target=”_blank” size=”medium” ]Minding the Markets: An Emotional Finance View of Financial Instability[/amazon_image]

This is intriguing. It certainly chimes with my unease (as in my Tanner and Pro Bono lectures) about the way economists talk – especially in the context of policy – as if they are omniscient outsiders, not part of what they are analysing. My question – which Prof Tuckett agreed is still-unexplored territory – is how reality interacts with our narratives, sometimes changing them. I’d like to have followed up by asking if the idea is a  paradigm shift, but in the domain of financial markets, or economic life in general, rather than scientific exploration.

Another conference highlight was Bridget Rosewell on the inadequacy of our standard cost-benefit approach for deciding whether or not to go ahead with transport infrastructure projects, inadequate because they use a comparative static, equilibrium framework for something that is bound to change the dynamics of the economy. She gave many examples of projects that would never have passed a modern cost-benefit assessment, from Bazalgette’s London sewers to the Jubilee Line Extension and – as she is scrupulous – an example of one that wasn’t making it in terms of her tale of self-fulfilling visions that deliver the benefits they subscribe. (This is the fantasy airport on Boris Island, which she supports.) Bridget touches on this infrastructure question in .

[amazon_image id=”1907994149″ link=”true” target=”_blank” size=”medium” ]Reinventing London (Perspectives)[/amazon_image]

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Economists and humanity

Peter Smith sent me his new book T. In a letter accompanying it, he said he has two motivations. One is to get economics out of the trap of over-simplifying so that models can use linear algebra and thus be made ‘tractable’. This is one of the things that makes complexity economics and agent-based modelling appealing; virtual economies run on a computer do not need to be solved algebraically.

[amazon_image id=”0957069707″ link=”true” target=”_blank” size=”medium” ]The Reform of Economics[/amazon_image]

The other aim is to make economic methodology something more like normal scientific methodology. Economic method consists of choosing some basic postulates and making deductions from them. The deductions can then be tested against data. Normal science involves both induction and deduction. Careful empirical observation will shape theory.

The book dates the choice of the purely deductive path to Lionel Robbins and his 1935 essay . He defined economics as the science of constrained choice, which, “Not only excludes uncertainty, but it also excludes from the scope of economics both institutions and the medium-term evolution of economic systems.” This isolates economics from the institutional framework of the economy, and hence from what determines the availability of resources over time – it makes economics an inherently static subject.

Natural scientists do regard economics as bizarrely non-empirical – I’ve been in multi-disciplinary conferences about both macroeconomics and behavioural choice at which biologists exclaim about how rarely economists discuss data, for all that they might go away and test hypotheses. One of the joys of being on the Competition Commission for eight years was how profoundly evidence-based the process is, and hence a real insight for an economist used to generalising about how companies behave. There aren’t many business people who think about marginal cost curves and production functions.

 is a game of two parts (not halves). It is mostly a critique of economic methodology but also has a useful introduction to agent based modelling. It ends on an upbeat note I very much like:

“Economics is becoming a much more interesting area in which to work and learn; and we have every hope that a more realistic and effective reformed science of economics will also be a more humane one. For, ultimately, economics is about the well-being of humanity.”

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