Tag Archives: review

Learning about (machine) learning

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Last week I trotted off for my first Davos experience with four books in my bag and managed to read only one – no doubt old hands could have warned me what a full-on (and rather weird) experience it is. The one (and that read mainly on the journeys) was The Master Algorithm by Pedro Domingos. I was impressed when I heard him speak last year & have been meaning to read it ever since.

The book is a very useful overview of how machine learning algorithms work, and if you’ve been wondering, I highly recommend it. On the whole it stays non-technical, although with lapses – and I could have done without the lame jokes, no doubt inserted for accessibility. The book also has an argument to make: that there is an ultimate ‘master algorithm’, a sort of Grand Unified Theory of learning. This was a bit of a distraction, especially as there’s an early chapter doing the advocacy before the later chapters explaining what Domingos hopes will eventually be unified.

However, the flaws are minor. I learned a lot about both the history of the field and its recent practice, along with some insights as to how quickly it’s progressing in different domains and therefore what we might expect to be possible soon. Successive chapters set out the currently competing algorithmic approaches (the book identifies five), explains their history within the discipline and how they relate to each other, how they work and what they are used for. There is an early section on the importance of data.

As a by the by, I agree wholeheartedly with this observation: “To make progress, every field of science needs to have data commensurate with the complexity of the phenomena it studies.” This in my view is why macroeconomics is in such a weak state compared to applied microeconomics: the latter has large data sets, and ever more of them, but macro data is sparse. It doesn’t need more theories but more data. Nate Silver made a simliar point in his book The Signal and the Noise – he pointed out that weather forecasts improved by gathering much more data, in contrast to macro forecasting.

Another interesting point Domingos makes en passant is how much more energy machines need than do brains: “Your brain uses only as much power as a small lightbulb.” As the bitcoin environmental disaster makes plain, energy consumption may be the achilles heel of the next phase of the digital revolution.

I don’t know whether or not one day all the algorithmic approaches will be combined into one master algorithm – I couldn’t work out why unification was a better option than horses for courses. But never mind. This is a terrific book to learn about machine learning.

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Growth, no growth, degrowth

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I just read the 2nd edition of Tim Jackson’s now-classic Prosperity Without Growth, which has been out for a few months, and it’s a book I’d recommend to anyone but especially economics students. Although most students do now learn about environmental constraints and trade-offs, we do socialize them quickly into thinking about economic growth as the objective of policy. It is all too clear that the failure to take account of externalities and the depletion of natural capital assets means we’ve paid a high price for past growth. Measuring these better to ensure they’re incorporated in the choices society makes is part of my own research.

Havings said this, and commending the book, I have one central problem with its argument, as with some others making similar arguments. And that turns on the understanding of what (GDP) growth consists in. Even those who acknowledge the importance of services in the economy – as Tim Jackson does – then consistently talk about growth as consumer demand for material products, for stuff: “How is it that with so much stuff already we still hunger for more? Would it not be better to halt the relentless pursuit of growth in the advanced economies and concentrate instead on sharing out the available resources more equitably?” So stuff and growth are conflated.

As I’ve been pointing out for 20 years, growth in the advanced economies is increasingly non-material – accepting that we import stuff embodied in goods, which must be accounted for. The archetype of modern growth is a new idea – that an aspirin can avert cardio-vascular problems as well as cure headaches; that apps on one device can replace multiple material objects.

This is why indicators like the Genuine Progress Indicator, that flatline from the 1970s on while GDP rises, are so unpersuasive. I disagree with Tim when he writes: “[T]he continued pursuit of economic growth doesn’t appear to advance and may impede human happiness.” So although I agree completely that the usefulness of GDP as a welfare measure is declining, I don’t think we know how to weigh against each other the environmental minuses and innovation pluses. This is why I’m obsessed with how we conceptualise and measure society’s economic welfare, including measuring assets to give us a handle on sustainability; but many of the innovations do advance human well-being. I remember the 1970s, and though the music was better, many aspects of life were far less satisfying. Patti Smith and Siouxsie & the Banshees aren’t enough to make me want to turn the clock back.

This is an important, possibly existential debate, so I hope the book is being widely read. I also appreciate its (only slightly lukewarm) defence of economics: contrary to the impression some environmetalists seem to give, many economists care passionately about our environment and sustainability, & we think our intellectual tools can make a useful contribution.

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Exact Thinking in Demented Times

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I bought Exact Thinking in Demented Times by Karl Sigmund for the genius title, and absolutely loved the book. The subtitle explains what it’s about: The Vienna Circle and the Epic Quest for the Foundations of Science. Karl Sigmund, the flyleaf tells me, is a maths professor at the University of Vienna and one of the pioneers of evolutionary game theory. He also co-curated an exhibition on the Vienna Circle, the inter-war group of philosophers, mathematicians and physicists who between them revolutionised the world’s understanding of – well, the world. Against idealism and metaphysics, seeking the unity of science, their logical positivism transformed Anglo-American philosophy, not least because so many of the Circle’s members had to flee Austria in the 1930s.

Who would have thought this could make a rip-roaring read? The book explains the philosophy and maths in just enough detail – there were a few bits about the maths I decided not to re-read – and weaves the ideas with the personalities, friendships and jealousies. It adds up to a wonderful intellectual history of a place and time. Jenny Uglow’s equally wonderful The Lunar Men would be a good comparator.

I’m not a big fan of logical positivism, or so I thought. Exact/Demented sent me back to my undergraduate copy of A J Ayer’s Language, Truth and Logic, which introduced the ideas to the British public (well, bits of it). I wrote the date inside, and I must have bought it enthusiastically in my first week at Oxford. Looking again reminded me how frustrating I found what seemed like meaningless quibbles about words – “easily understood by the layman”, the back cover claims. Hah! However, Exact/Demented gives a much richer account of the strands of thought in the Vienna Circle and makes it clear that the linguistic rabbit hole was but one element of the underlying empiricism. The account also completely reinforces my belief that Wittgenstein’s work is objectively meaningless and what’s more he was a complete pillock. (Although when I tweeted something from Douglas Hoftstadter’s intro to the book to the same effect, it turned out there are a few pro-Wittgenstein trolls on Twitter, so I’ll get into trouble with them again.)

Other obvious characters feature in the story, such as Kurt Godel, Rudolf Carnap and the positivism critic Karl Popper, as well as Einstein, and lesser known (to me) people, including the Circle’s leading light Moritz Schlick, and some economists orbiting around (Oskar Morgenstern, John von Neumann). The story is bookended by two murders of philosophers, and two tragic world wars. The Vienna Circle survivors ended up split between universities in the US and UK – on one occasion Bertrand Russell, Albert Einstein, Kurt Godel and Wolfgang Pauli all ended up socialising in Princeton, discussing time travel. What an occasion.

Given my own research interest at the moment, I was particularly pleased to learn about Otto Neurath’s innovative data visualization method, through his Institute for Pictorial Statistics, designed to present socio-economic statistics in a form most people could understand. The signature style was the use of rows of little human figures, which ended up being called ‘Isotype’. Who knew infographics were invented in the 1930s?

Poignantly, in 1939 Otto Neurath published a bestseller called Modern Man in the Making. “It employed a tight mesh of texts and pictures to describe the dawning world of globalized exchange, international migration and limitless progress.” How his readers must have been wishing that were true.

And this is the other attraction of this wonderful book. Its subtext throughout is both the need for and the threat to Exact Thinking in Demented Times, a message relevant today.

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From ‘Arab Spring’ to Fake News

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I’m late to Zeynep Tufekci’s excellent Twitter and Teargas: The Power and Fragility of Networked Protest. It analyses the impact of social media on political events such as the Arab Spring – remember that? – and Occupy. Her thesis is that online organization is a powerful political tool when combined with offline organization, but cannot substitute for it; and the evidence presented here from a range of mass protests certainly convinces me. The problem mass socially-networked protests have lies in their norms of decision making, which are slow and non-hierarchical. This makes them unable to change tactics quickly when hostile authorities respond to the protest, and so the moment passes. If, however, there is a parallel offline organisation with more conventional decision-making structures, the political protest can adapt and continue.

The book is informed by the author’s experiences visiting protests since long before Twitter and Facebook (and this makes it an engaging read). There is a lot of intriguing detail. Why, she asks, do longer-lived protests like Occupy Wall Street or Gezi Park set up libraries? Even clinics and clothing exchanges are probably unnecessary. She argues that the spirit of protest involves expressiveness – taking part is a meaningful or even joyful activity, often with a sense of ritual or transcendence..

A later interesting section of the book concerns the way authoritarian governments are fighting back against protests using social media themselves – not so much by cutting off the internet (which happened more in the early, Arab Spring, days than it does now) as by flooding social media with confusion and false information. I think the book was written before we all became familiar with the phrase Fake News, but here it is presented as a tactic of repression. Even in tightly controlled China, online comment is rarely shut down unless it looks like becoming organised offline action.

All in all, a highly recommended book, albeit not a particularly cheering one. The Arab Spring feels a long time ago, those days when democracy looked like it was still spreading rather than retreating. Tufekci herself ends on a slightly positive note, reporting a conversation with a young activist (one of Sain’s Indignados) about where things might go. The young woman replies with a phrase echoing one the Zapatistas used much earlier: “We will keep walking and keep asking questions.” As long as pepole have the energy to keep on, there’s hope.

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I read the book on my trip to the ASSA meetings, also reading Darren McGarvey’s Poverty Safari, a second book by the wonderful new discovery Mick Herron, and Svetlana Alexievich’s Boys in Zinc. All highly recommended.

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No escape from the target setting arms race?

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Among my holiday reads has been Jerry Muller’s The Tyranny of Metrics, published in the UK in a couple of weeks (can be pre-ordered now). The broad thesis of the book, which is a lively read, will be familiar to readers of the literature on the gaming of public service targets. This short book is stuffed with examples of the counter-productive results of insistence on numerical targets.

There is an interesting chapter on the origins of metric-fixation (at least in capitalist economies – the Soviet Union was always rather keen on it), which starts: “The demand for measured accountability and transparency waxes as trust wanes.” Social change following the explosion of protest against authority in the 1960s and the erosion of the post-war class certainties contributed to this process. So did the evident failures in public services and nationalised industries by the 1970s. But as the book goes on to note – and has been explored in the academic literature – public services are not like businesses, having a larger, complex set of aims and depending fundamentally on intrinsic motivation. A thriving public sector is important to the health of the wider economy: “A capitalist society depends for its flourishing on a variety of institutions that provide a counterweight to the market with its focus on monetary gain.”

The book goes on to give a range of examples of targets turned counter-productive in arenas from higher education to medicine and policing to business. Yes, business too. For here targets are linked to remuneration. Yet, as the book notes, economic theory (Holmstrom and Milgrom, as I describe here) and evidence point firmly away from rewarding the attainment of targets whenever individual effort is un-monitorable. Not that this has prevented to spread of performance pay or bonuses, Muller observes: “Although there is a large body of scholarship in the fields of psychology and economics that call into question the premises and effectiveness of pay for measured performance, that literature seems to have done little to halt the spread of metric fixation.” The book ends with a section describing how to use targets intelligently – think about what you’re trying to measure, why and for what purpose. Above all, think. The frustration is that it offers no thoughts about how to roll back the vast swathes of counter-prouctive targetry already afflicting us. Just imagine the outcry if any politician promises a ‘bonfire of the targets’ or less transparency. On the contrary, the arms race seems as intense as ever – when the pitfalls of one type of target are recognized, the solution is more complicated metrics. But dearmament is what we need.[amazon_link asins=’0691174954′ template=’ProductAd’ store=’enlighteconom-21′ marketplace=’UK’ link_id=’77f90151-ea50-11e7-b438-4348033ba2bc’]