Trusting Experts

By Sean Carroll | September 13, 2011 12:40 pm

Over on the Google+, Robin Hanson asks a leading question:

Explain why people shouldn’t try to form their own physics opinions, but instead accept the judgements of expert physicists, but they should try to form their own opinions on economic policy, and not just accept expert opinion there.

(I suspect the thing he wants me to explain is not something he thinks is actually true.)

There are two aspects to this question, the hard part and the much-harder part. The hard part is the literal reading, comparing the levels of trust accorded to economists (and presumably also political scientists or sociologists) to the level accorded to physicists (and presumably also chemists or biologists). Why do we — or should we — accept the judgements of natural scientists more readily than those of social scientists?

Although that’s not an easy question, the basic point is not difficult to figure out: in the public imagination, natural scientists have figured out a lot more reliable and non-obvious things about the world, compared to what non-experts would guess, than social scientists have. The insights of quantum mechanics and relativity are not things that most of us can even think sensibly about without quite a bit of background study. Social scientists, meanwhile, talk about things most people are relatively familiar with. The ratio of “things that have been discovered by this discipline” to “things I could have figured out for myself” just seems much larger in natural science than in social science.

Then we stir in the matter of consensus. On the very basics of their fields (the Big Bang model, electromagnetism, natural selection), almost all natural scientists are in agreement. Social scientists seem to have trouble agreeing on the very foundations of their fields. If we cut taxes, will revenue go up or down? Does the death penalty deter crime or not? For many people, a lack of consensus gives them license to trust their own judgment as much as that of the experts. To put it another way: if we talked more about the bedrock principles of the field on which all experts agreed, and less about the contentious applications of detailed models to the real world, the public would likely be more ready to accept experts’ opinions.

None of which is to say that social scientists are less capable or knowledgable about their fields than natural scientists. Their fields are much harder! Where “hard” characterizes the difficulty of coming up with models that accurately capture important features of reality. Physics is the easiest subject of all, which is why we know enormously more about it than any other science. The social sciences deal with fantastically more complicated subjects, about which it’s very naturally more difficult to make definitive statements, especially statements that represent counterintuitive discoveries. The esoteric knowledge that social scientists undoubtedly possess, therefore, doesn’t translate directly into actionable understanding of the world, in the same way that physicists are able to help get a spacecraft to the moon.

There is a final point that is much trickier: political inclinations and other non-epistemic factors color our social-scientific judgments, for experts as well as for novices. On a liberal/conservative axis, most sociologists are to the left of most economists. (Training as an economist allegedly makes people more selfish, but there are complicated questions of causation there.) Or more basically, social scientists will often approach real-world problems from the point of view of their specific discipline, in contrast with a broader view that the non-expert might find more relevant. (Let’s say the death penalty does deter crime; is it still permissible on moral grounds?) Natural scientists are blissfully free from this source of bias, at least most of the time. Evolution would be the obvious counterexample.

The more difficult question is much more interesting: when should, in completely general terms, a non-expert simply place trust in the judgment of an expert? I don’t have a very good answer to that one.

I am a strong believer that good reasons, arguments, and evidence are what matter, not credentials. So the short answer to “when should we trust an expert simply because they are an expert?” is “never.” We should always ask for reasons before we place trust. Hannes Alfvén was a respected Nobel-prizewinning physicist; but his ideas about cosmology were completely loopy, and there was no reason for anyone to trust them. An interested outsider might verify that essentially no working cosmologists bought into his model.

But a “good reason” might reasonably take the form “look, this is very complicated and would take pages of math to make explicit, but you see that I’ve been doing this for a long time and have the respect of my peer group, which has a long track record of being right about these issues, so I’m asking you to go along this time.” In the real world we don’t have anything like the time and resources to become experts in every interesting field, so some degree of trust is simply necessary. When deciding where to place that trust, we rely on a number of factors, mostly involving the track record of the group to which the purported expert belongs, if not the individual experts themselves.

So my advice to economists who want more respect from the outside world would be: make it much more clear to the non-expert public that you have a reliable, agreed-upon set of non-obvious discoveries that your field has made about the world. People have tried to lay out such discoveries, of course — but upon closer inspection they don’t quite measure up to Newton’s Laws in terms of reliability and usefulness.

Social scientists are just as smart and knowledgable as natural scientists, and certainly have a tougher job. But trust among non-experts isn’t demanded, and shouldn’t be based on credentials; it is given on the basis of a long track record of very visible success. Everyone would be in favor of that.

CATEGORIZED UNDER: Science and Society, Top Posts
  • J-Doug

    As a social scientist and a professor who teaches his students never to accept authority blindly (in matters of social science, at least), I think your final point is spot on (and more important than your first two). People have more of an incentive to accept or disregard authority in socio-economic and political matters–such as the Laffer Curve–whereas few people tie up their identity with supersymmetry or the germ theory of disease, for example.

    The obvious exceptions are evolution and global warming.

  • edward hessler

    There is a large literature which shows that we are very active in forming our own ideas of how the world of physics works. Many of these turn out to be wrong to varying degrees and these were first termed as misconceptions/alternative explanations (plus more than a 100 other terms/phrases).

    Research on misconceptions also shows that they are extraordinarily resistant to change and physics professors who have taken time to interview their students or use any of the various conceptual inventories (e.g., The Force Concept Inventory) know these difficulties. A number of physics departments have their own programs/research groups that deal with physics education, e.g., the University of Maryland, University of Massachusetts, University of Washington, University of Colorado, University of Minnesota) and Harvard University physics professor, Eric Mazur pioneered an intervention program in large lecture conditions to deal with these (His research site has many useful papers on teaching with concept learning in mind.). And one Nobel prize winner, Carl Wieman, has turned from physics research to the improvement of physics education, especially at the college level, emphasizing the need for a scientific approach to science education.

    The K-12 education reform document, Benchmarks for Scientific Literacy (Project 2061, AAAS) had a chapter (The Research Base) documenting the most common misconceptions in science but it is very much outdated.

    An Internet search on misconceptions in physics (as well as chemistry, biology, earth science) will lead to many interesting and revealing papers as well as provide useful resources (inventories in particular) that can be used to improve teaching.

  • Jason Dick

    Great post! Unfortunately, from learning about economics over the past few of years since this crisis hit, I’ve come to understand that the following statement simply isn’t possible:

    “So my advice to economists who want more respect from the outside world would be: make it much more clear to the non-expert public that you have a reliable, agreed-upon set of non-obvious discoveries that your field has made about the world.”

    This is because there simply isn’t an agreed-upon set of discoveries in economics, period, due to the splintering of the field, most significantly between the sometimes-named “saltwater” and “freshwater” schools. However, it seems to me that an interested observer can, without too much difficulty see which school, if any, better approximates reality. And you can do this by asking the following questions:

    1. Does this expert use a specific economic model? Can I understand this model, and confirm it predicts what this expert claims it predicts? (Usually, though not always, macroeconomic models are pretty simple.) If there doesn’t appear to be a model in use, just lots of ad hoc justifications, look out!
    2. Have the predictions of this expert stood up to reality? This is most easily tested by looking at easily-calculated phenomena, such as interest rates, inflation, GDP, etc.

    Using these criteria, it seems to me that economists such as Paul Krugman, Brad DeLong, and Mark Thoma are quite good (Greg Mankiw, not so much). Some examples of confirmed predictions since this crisis began:
    1. It was going to be a jobless recovery.
    2. The original stimulus package was too small, such that the economy was likely to continue to languish.
    3. Despite the large increase in government deficits, interest rates on government debt were likely to fall.
    4. Despite interest rates near zero and quantitative easing, inflation was likely to continue to fall.

    So it seems to me that there is a specific school of economics that has come through this crisis with flying colors. It is sad that so much of the economic profession has not.

  • Low Math, Meekly Interacting

    It’s difficult to avoid a certain level of skepticism when considering the interminable and heated debates over the theories of John Maynard Keynes and Milton Friedman. Both won the Nobel Prize, and beyond that there’s little professional consensus, nor do I expect there to be. Study of the natural sciences lends itself to the quest for greater and greater accuracy, and defeat of bad ideas is a matter of experiment and consistency. The social sciences are in a more difficult position, but it appears to be exacerbated considerably by their practitioners, who not only lay claim to authority, but occasionally are called upon to shape social policies in profound ways. Had more of them been able to admit how tenuous their true grasp of real-world social phenomena was, they might not be in the position now of defending their very relevance. I look at economics, and I see the occasional prophetic scholar railing against the storm. But the field? I find it difficult to categorize. It’s social, to be sure. But science?

  • Markk

    It’s isn’t hard, its simple. We have done the experiments in the physical sciences. Over and over. Millions of time we have tested and do test through engineering the models used by the scientists. Every time we use a computer, drive a car, use an antiseptic we ourselves do little tests and get a little more confidence in the people that designed them and the models that they used. There are millions and millions of examples of this. Basically there is nothing like civil, electrical or mechanical or chemical engineering in the social sciences that is integrated into societiy as much as traditional engineering. It is the engineering everybody sees that makes the scientific background of physics and chemistry so much more believable.

  • Arun

    This is a problem – which experts to trust – that has occupied me on and off for the longest of times. I think good recipes here – there are no algorithms – are essential for an informed citizenry.

    1. Find out what the opposing experts say.

    2. Look at some of the literature, even if it is Greek to you. Trace out papers (using the Citation Index) to see reactions to what your expert wrote, look for agreement and dissent – don’t just rely on third parties. Get some idea of the weights on either side of a controversy.

    3. Take one small area of controversy, if you can, and study it in detail. Sometimes it becomes clear that the weight of logic is very lopsided. Try to see if you can spot which experts are presenting the whole truth, and which experts are “lawyering”.

    4. Beware of narratives that sound very plausible but don’t provide a wide view of the data. A recent example that happened to me – Fact: corporations have a lot of cash. The claim was – corporations are hoarding cash because banks are reluctant to lend after the financial crisis of 2008. On further examination – it turns out that corporations have been increasing their cash-to-overall asset ratio since the 1980s, doubling between 1980-2004; and the 2010-11 statistics are supposedly in accord with this long-term trend. ( Further-further examination – not yet done.) The danger I’m pointing out is that the narrative sounded so plausible that I might have blindly accepted it.

    5. Try to grasp the structure of the argument even when you can’t follow the substance. E.g. simple example, if you come across a pair of papers, the first of which says, I will assume this result which I will demonstrate in a subsequent paper, and then the second paper assumes something that was shown in the first paper, be very suspicious. Not necessarily anything wrong, but it doesn’t smell good. Good prevaricators manage to hide the handwaving much better, though :(

    6. Remember that verifying claims is typically a Polynomial Time problem; coming up with a good new theory is typically a NP-complete problem. Likewise checking up someone’s explanation for something is typically far easier than coming up with a good explanation for something. Your job is to find experts that you trust, not to become an expert.

    7. The side that talks in terms of a model is likely more right than the side that simply strings together a set of plausible arguments, unsupported by data.

    A good warm-up exercise is to examine for yourself the literature on something like cold fusion and see if you can arrive at the consensus opinion for yourself.

  • Neal J. King

    The field of economics is at the level of scientific maturity that I would characterize as pre-Newtonian.

  • kyle

    is this a joke?

  • Philoponus

    Look, it’s not clear to me that I ever have to (or ought to) “trust” in the work of theoreticians of any ilk. “Sean Carroll believes that T” is never evidence that T is true (though it may be grounds that I should take seriously and inquire into his grounds for believing that T). We are not medieval Scholastics, counting the number of authorities who support T and the number who reject T, and concluding the higher number is likely right.

    The situation is very different in applied fields like medical research. If I have a parent slipping into Alzheimer’s, and Art Horwich (this year’s Lasker Prize winner) says intranasal insulin therapy looks very promising although we have only prelim data, I have to make a choice. I can’t replicate his research, I have to trust that his protocols are sound, and I have to decide whether to subject a failing parent to therapy that could do no good and possibly some harm. Here I have to trust and act.

  • Ted Davenport

    Sean said: “Social scientists are just as smart and knowledgable as natural scientists, and certainly have a tougher job.”

    This is horseshit. Take your false humility and shove it.

  • very surprised

    Economics is actually physics in disguise. Once one understands that most of economics is just partial derivatives of certain curves, it all comes together fairly quickly.

  • Mike

    Arun @6,

    What a very useful post. I hope that I try and do all of these things. I was very interested in your point 4. What a perfect example of where people can go wrong. Again — good job!!

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  • On another note

    I think people confuse difficulty in comprehending theory with execution in practice. Economic theory can be dense to the uninitiated, but in general the basic mathematical description is fairly simple. One can do a lot in microeconomics without going further than linear algebra.

    In practice microeconomics is extraordinarily complex because it is difficult to define any notion of value that is universally agreed upon. So it becomes reasonable that those who practice economics can become a little defensive because there is a lot of art that is not readily translatable into theory.

    Certain experts can become indignant, but I don’t think most economists can make the bridge to generalizing their research in such a way that they can claim it as a science.

  • John Emerson

    Mark Thoma:

    “There is no grand, unifying theoretical structure in economics. We do not have one model that rules them all. Instead, what we have are models that are good at answering some questions – the ones they were built to answer – and not so good at answering others.”

    Economics is more like a craft wisdom or a toolbox than like a theoretical science. This doesn’t mean it’s useless or meaningless, just that it shouldn’t claim to be like physics. I don’t think that it should be expected to be, or try to be, like physics. As said above, it’s a tougher job dealing with more difficult systems. Physicists who drop down to easier sciences sometimes do great things (Crick and Watson) and sometimes they mess up (most of theoretical economics, and the quants).

    A lot of times scientists seem to be trying to establish pecking orders rather than to understand other sciences. Physicists have been cited as doubting that biology is a science, since it fails to meet certain standards that physics can meet. According to Philip Anderson (Nobelist), quantum physicists even sneer at condensed matter physicists, of which he is one. Some of it is like

  • John Emerson

    One problem not mentioned is that everything economists study is controversial and has major effects in the lives of human beings. Nobody really cares about [string theory or whatever the cutting edge field is in physics], and no one will get rich or have their life ruined if one theory wins out.

  • Christopher@BorderWars

    I think there’s also the aspect of “what does this have to do with me?” bias between a physicist and sociologist. Most laypeople have no specific reason to care what new universe the next new telescope is going to find, but they have a lot of buy-in on expert policy on things like end of life care or employment benefits or taxes.

    Those are also the issues people are likely to have an a priori opinion of, thus expert testimony will not be the first exposure to the topic and thus more likely to cause distrust if the expert opinion is contrary to established beliefs.

  • Gary

    Microeconomics is relatively close to being a falsifiable area, macro is a bit like alchemy was in Newton’s day – although Newton himself spent a lot of time on it!

    For example, they have a so called Nobel prize in economics and one year they gave it to Myrdal and Hayak simultaneously which is rather like giving two Fields medals out: one for supposedly proving a result and the other for finding a counterexample.
    At best Macro has rather too much phlogestin floating around inside of it, at it’ worse (as practiced by the so called fresh water guys, it is basically as if we all decided to do astrology only using really fancy non linear math to do the calculations,

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  • Kaleberg

    If physicists argued that water runs uphill, if chemists argued that wood could not burn because it contains carbon, if biologists argued that fish cannot live underwater, then I’d trust them as much as I trust economists. In fact, I’ll cut anyone a little slack. Science and the world are full of surprises, but when the experts are consistently and repeatedly wrong, I will not deny them their hard earned disbelief.

  • rgb

    “Explain why people shouldn’t try to form their own physics opinions, but instead accept the judgements of expert physicists, but they should try to form their own opinions on economic policy, and not just accept expert opinion there.”

    Not sure about the original question: I would have thought that people should try to form their own physics opinions among other things. Of course, forming informed opinions takes time, which people only have finite amounts of. Now, with physics, one has to be really interested (many of those probably end up as physicists anyway) because more often than not he/she’s opinions will not have much effect.

    Social science on the other hand, one has to be aware of. In order to live in society responsibly we have to make choices that affect the society (for example vote) or us personally. Therefore it is essential to decide which of the experts is right. For physics the stakes are not as high

  • Jimbo

    Au Contraire, Monsieur !
    If there was ever a time when non-physicists should try to formulate their own opinions about the makeup & functioning of the physical world, it’s NOW.
    As of today, string theory, based critically upon SUSY, appears to be utterly incapable of predicting any aspects of the std. model; the LHC has excluded SUSY out to 700 Gev. Large extra dimensions, probed out to 7 Tev, have not manifested as mini-black holes or any other predicted processes. Most of the parameter space in which Higgsy might be hiding, has been excluded. Cutting edge theoretical ideas, such as Verlinde’s holographic interpretation of gravity, has been shown to be at odds with established falling neutron measmts. Most incredibly, the INTEGRAL satellite has recently found evidence that the real quantum gravity scale may lie an incredible 14 decades beyond the Planck scale at 10^- 49 meters.
    In short, all of the `established’ canon for physics signatures beyond the standard model appears to have fell on its collective face, after 40 yrs of waiting. This situation is unprecedented in modern physics, & we need bright, creative minds to throw down the gauntlet & introduce new ideas in the vacuum of failed ones conceived & nurtured by the physics establishment.

  • Greg Ransom

    “a reliable, agreed-upon set of non-obvious discoveries”

    1. Economic coordination via central planning is impossible in an extended economy.

    2. The elimination of interest rates is impossible in an extended economy,

    3. Extended economic coordination without money & money prices is impossible.

    4. The determination of a “just price” is impossible.

    Generations of people have thought that all of these were possible — many non-economists still do.

  • Greg Ransom

    There couldn’t be anything more useful than to disabuse people of the mistaken belief that it possible to centrally plan an extended economy, or that it is possible to determine a just price, or that it is possible to do away with private property and money and money prices, or that it is possible to do away with interest.

    Many of the greatest human tragedies of modern times were due to failures to grapes these surprising and useful discoveries, discoveries due to great scientists stretching back to the Spanish schoolmen.

  • Greg Ransom

    “a reliable, agreed-upon set of non-obvious discoveries”

    1. It is impossible to “control prices” — “controls” merely increase costs & shift them elsewhere, block communication signals, and cripple the discovery process of competition.

    2. it is impossible in advance to know where rivalry and competition will take you; it is similarly impossible to advance into the unknown without the use of the discovery procedure of rivalry and competition, where each is allowed to explore his own unfolding understanding of local conditions in coordination with others via price signals.

    3. It is impossible to control the price of interest, the stock and velocity of money, and the degree of leverage and liquidity in the extended economy without distorting the coordination of economic plans over time in a fashion which will leave many inputs to production “out of work” when time reveals an unsustainable pattern of production plans.

  • Greg Ransom

    Could there be anything more useful than to know what causes economic cycles — and what needs to be avoided in order to not to create massively destructive cycles?

  • TheRadicalModerate

    There’s a much simpler explanation: ordinary people don’t trust scientists; they trust engineers. Physics and the other hard sciences have long, successful engineering histories associated with them, so they get lots of trust. Biology and medicine have slightly less engineering, and therefore slightly less trust. Economics only has finance as its companion engineering discipline, and the success of finance is less than stellar. As for the social sciences–there ain’t no stinkin’ engineering, and therefore there ain’t no stinkin’ trust, either.

    This is, IMO, the main problem that climate science is having right now. They have some results, but there’s absolutely nothing they can engineer to make things better (or at least better enough to warrant the cost), so the public remains skeptical.

  • Bee

    The problem is that in the public’s eye economic models mix with economic opinion. The first is what (ideally) can scientifically be stated, the second is the question what you want to do with that knowledge.

  • kitov

    People do trust physics and physicists in every day activity. Aircrafts, ships, buildings in seismic zones, TV, mobile telephony, etc. is the material realization of scientific knowledge.
    New horizons in physics are not for the broader audience and do not have robust realizations yet.

    Theoretical macroeconomics (I do not include micro, finances, business, etc.) is a science without actual realizations when one can foresee important outcome. (We foresee that our airplane will land with a very high probability. Otherwise we would never use it.) Some physicists propose a scientific revolution in economics (Bouchaud, J.-P., (2008). Economics needs scientific revolution, Nature, v.455, 30 October 2008) . I would start with a simple data analysis in line with classical mechanics (Ivan O. Kitov, 2009.
    “Does economics need a scientific revolution?,”
    Quantitative Finance Papers 0904.0729,
    Actually, economic data do not match even basic requirements of physics. They are usually incompatible over time. One needs lots of patience to recover major time series like inflation, GDP per capita, rate of unemployment, etc. (

  • Joshua Zelinsky

    You are correct to bring up the issue of political inclinations and ideologies having more of an impact on the social sciences. However, I think that you underestimate the importance of this aspect. I would suggest that the actual problem is almost completely due to political ideologies interfering. The strongest evidence for that is that there are areas of the hard sciences where people reject the science simply due to their religious or political leanings. Evolution and global warming would be the two most prominent examples.

  • chris

    that’s an easy one.

    while in physics there are clear answers to clear questions, in economics the guess of the average layman is as good as that of the last nobel laureate.

    just as an example: i once saw the correlation between the 2-year prognosis for gdp growth vs. the actual growth. the correlation was actually negative :-)

  • Alex D

    It’s all about error bars 😀

    In physics, the Standard Model + General Relativity account for ALL observed experimental data with only a handful of model parameters. Perfect predictions, zero error bars.

    In economics, there is no theory analogous to the standard model of physics. Candidate macro- and micro-economic theories have modest predictive power at best. Therefore, none of those theories are “right” and are at best approximations of a full and correct theory (assuming one exists). Poor predictions, large error bars.

    The original question was: “Explain why people shouldn’t try to form their own physics opinions, but instead accept the judgements of expert physicists, but they should try to form their own opinions on economic policy, and not just accept expert opinion there.”

    My answer is that people are free to form whatever opinions they like, but probably shouldn’t feel the need to try to improve upon a physical theory which has perfect predictive power. It’s more reasonable to want to form your own opinion about economics because it’s a subject in which models and expert opinions have poor predictive power = big error bars! I’m not saying that it’s easy to come up with a better economic theory, only that it’s natural to find the existing theories lacking.

  • bs

    Explain why people should reject predictions of soothsayers and astrologers out of hand, and not reject judgements of expert economists in the same way.

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  • Greg Ransom

    In Darwinian biology there is no theory analogous to the standard model of physics, ditto a dozen other powerful explanatory domains within science.

    So what?

    “In economics, there is no theory analogous to the standard model of physics.”

  • Greg Ransom

    The biggest problem isn’t that there has been massive explanatory success in economics, providing lessons for mankind of the most signal importance: the names Mises & Hayek come to mind.

    The big problem is how much fake science is produced by tenured professors within economics department attempting incompetently to imitate very tiny slices of what is done in the math & physics department — all while attempting satisfying the philosophical demands of failed philosophical projects from generations ago. See on this particularly the work of Friedrich Hayek, Bruce Caldwell & Philip Mirowski, among many others.

    The word “scientism” was coined by Hayek to capture this epic FAIL by the tenured professors in the economic departments.

  • Low Math, Meekly Interacting

    I think I have a good metaphor to illustrate my skepticism and concern about economics (the field as a whole): Everyone needs to assume the spherical cow from time to time. The problem with economists is that, once the cow has been show to be non-trivailly aspherical, they proceed to tell us that obviously real cows must have been ruined by cultivation, and then, as a group, provide a litany of often mutually-exclusive remedies to bovine asphericity.

  • Joseph Hertzlinger

    Lots of people distrust physicists. We can start with anti-nuclear-power activists and continue through young-Earth creationists, astrologers, people who think that quantum mechanics means that refusing to perceive something means it doesn’t exist, etc….

    Have you ever tried telling a liberal activist that depleted uranium is relatively harmless?

  • Barry

    @28 The Radical Moderate:

    “This is, IMO, the main problem that climate science is having right now. They have some results, but there’s absolutely nothing they can engineer to make things better (or at least better enough to warrant the cost), so the public remains skeptical.”

    No, the main problem that climate science is having is a lavishly funded campaign of lies and fraud.

    However, your point on trusting engineering, not science per se, is great.

  • Charlie

    But plasma cosmology must be true. Why else would all the “experts” deny it?

  • Len Ornstein

    Building models requires consistent use of agreed upon axiomatics; that is, definitions of fundamental terminology and the equivalent of syntactic and grammatical rules, in order that they will be similarly perceived by participants in a ‘discussion’ of their usefulness.

    Scientific models (ideas, speculations, theories and ‘Laws of Nature’) depend upon consistency with such agreed upon foundations. And science ALSO requires that predictions/projections of models are supported by empirical ‘observations’ of ‘reality’. The more pertinent, the more unbiased and the more frequent the support, the higher the confidence in the model.

    The models of mathematics, religions and numerous other disciplines also supposedly require ‘faith in’ their axiomatics and consistency in their application. But they usually do not require empirical confirmation.

    For example, “demand side” and “supply side” economics have different axiomatics – and no consistent empirical support for the predictions of either – in fact, many horrendous failures! They are more nearly dogmatic ideologies than ‘science’. That’s the main reason their experts should not be trusted.

    In scientific fields, where models have received empirical support at high levels of confidence – which can usually be witnessed by a high level of consensus among the specialists in those fields – experts may be worth trusting.

    Obviously, IF one knows enough about the axiomatics, the models and/or their empirical ‘record’, you may not need to rely on expert opinion.

  • Olli Pehkonen

    Economics can be said to have been slow to make progress compared to, say, physics in the last century or so. You should however keep in mind that some progress has been made. If you look at the great depression in the 30ies you will see that unemployment rates in the USA were around 20%, where in this crisis the rates are around 10%. One of the reasons is what we have learned from economics.

    The idea of a balanced budget (ironically being debated in USA politics) should be applied only over a longer period than a fiscal year, maybe even longer than a decade. During the great depression the US goverment tried to keep a balanced budget and thus deepened the depression. This happened because when there is less economic activity, there are less taxes paid. If the government tries then to keep a balanced budget, they will have to also cut down on spending, causing more people to lose jobs, less taxes again, less government spending again, less jobs again…

    We understand this now and thus are not likely to experience recessions as deep as the great depression anymore, at least not due to the business cycle. There are important lessons that have been learned in economics too, just they tend to come slowly.

  • ezra colbert

    Ask yourself: how passionate am I, personally, about
    the mass of the proton
    role of quarks as constituents for protons

    we are descended from monkies
    sex ed decreases sexual activity in teens

    I think one thing we do learn from psychologists is that people disregard facts if the facts conflict with beliefs; since most of us don’t have, or don’t care that much about the mass of the proton, there is no problem with accepting experts.

    Also, the “hard” scientists are probably better at hiding their errors; I mean, someone publishs a math heavy paper on proton mass that is wrong, it is not exactly front page news….

  • onymous
  • Jim Harrison

    Economics is more like formal linguistics than physics. It depends on a mostly theatrical show of mathematical rigor to distinguish itself from the rest of sociology just as the generative grammar folks of the 60s made a big deal out of tree diagrams and other paraphernalia to impress the natives. Empirical confirmation? No so much. That doesn’t mean that economists don’t have some valuable ideas, just that the state of economics as a whole is rather like what we’d be dealing with if astronomy and astrology were still just one subject.

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  • Chris

    One quibble: social science theorists do consider moral issues. My girlfriend is a political theorist (Department of Political Science) and her candidacy reading list ranged from Plato and Aristotle through to Hobbes, Locke, and Hume, and on to Mill, Nietzsche and Rawls. A good social science theorist will tackle questions to which, in principle, there are no correct answers.

    In other words, proper social science is not all just sociological and economical phenomenology, fields in which there presumably are true/false answers regarding causation. Even model-makers in these true/false fields need abstract concepts like Identity or Utility, and no one contends that these things are “out there in the world” in the way that we physicists convincingly interpret out abstract theoretical entities.) So we probably shouldn’t insist that the success or failure of all lines of social-scientific inquiry be decided solely or even at all by number of “things that have been discovered” or consensus among practitioners.

    (Then why call them a science? That’s an active-ish debate within the social sciences themselves, although as opposed to the humanities even interesting ideas are ideally dropped if they don’t “work” or have explanatory power – a bare-bones scientific method.)

  • Gizelle Janine

    I agree/disagree on too many levels to mention but…

    I think the question in general enraged me quite a bit in regards to science, specifically I thought about what theory happens to be, and generally what the scientifc method is. I dont know I could be brain dead and not know it.

    Great post. 😀

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  • Simon

    Late to the party… but:

    I’ve studied both physics and sociology (politics/economics) at degree level.

    Physics is much, much harder to study than sociology, because so much deep thought has gone into it by so many very clever people. It’s been a proper science for 300 years, and has got to the point where even the best and the brightest are struggling to make headway, very little fundamental theoretical progress has been made since the 80s.

    Sociology, on the other hand is relatively easy to study, the hardest part is working out what people are trying to say behind the bluster and faux technical language. Most sociology is phenomenology – fundamental theoretical progress is stymied by the vast array of confounding factors in any experiment. Because of this, much of what could be theoretical foundation is closer to opinion.

    To answer the original question:

    If in 1990, I’d asked 20 physicists about, I dunno, the quantum states of an electron in a hydrogen atom, I’d have got 1 answer (perhaps after a bit of surreptitious page flicking).

    If, in 1990, I’d asked 20 economists whether the UK should be part of the Euro, I’d have got 3 answers: yes, no, maybe, in roughly equal proportions.

    Asking the same questions today, I’d get the same answer from the physicists, but very different answers from 2/3 of the economists.

    Economists are unreliable, and prone to see the evidence that backs up their personal opinion.

  • JMW

    I think part of the problem, too, is the politicization of all these spheres of inquiry.

    Economics (at least in the U.S.) long ago became dominated by the “Chicago School” of Milton Friedman, et al. They colonized various institutions such as the US Dept of Finance, the World Bank, and exported their brand of economics to various other countries that were experiencing fiscal instability. The result was a wave of austerity programs and massive cuts in government spending in these countries. In my humble opinion, these cuts probably went too far, but that’s subject to debate.

    But in any event, Chicago School was driven by the right-wing, libertarian philosophy of “government = bad”, “free enterprise = good”…or even “free enterprise = godliness”. To say nothing of a theory of how society should be run, how government should be run, etc., extending what was an economic theory into the realms of philosophy of government and theories of social engineering, areas with which economics has only tenuous connection. I find this dichotomous view too simplistic, but that’s just my opinion.

    But from there, the political spin meisters realized that they could turn everything into politics, and over the last few decades, they’ve succeeded. Now we evaluate everything through the lens of politics.

    But scientific fact is politically neutral. The gravitational lensing of light doesn’t care if the person observing it is left wing or right wing. Neither does the temperature or acidity of the oceans, the temperature of the air, nor the extent of sea ice in the Arctic. But the political strategists succeed in making us think first about how all these facts affect us politically, rather than environmentally or how it affects our capacity to house and feed people.

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  • Laura

    I would like to see the DATA to back up the statement that social ‘science’ is harder than natural science! Really?! Was the scientific method used to validate that statement. I wonder how often in social ‘science’ the scientific method is used. Why is it called social ‘science’ anyway? It is truly a science?

  • kitov

    I would not say that economics is as “hard” as classical mechanics. At the same time, geophysics and, specifically, seismology (my profession) do belong to the hard sciences with the overall uncertainty in principal relationships higher that that estimated for the following macroeconomic variables (validated by statistics as adopted in physics):
    inflation (deflation) – or

    unemployment –

    real GDP –

    Labor force participation rate –

    It is up to you to judge the accuracy and reliablity. It might be too early to call my own blog “Economics as Classical Mechanics” but we all should be interested to make economics a hard science in our understanding of this term.

  • Marc Sher

    Completely off-topic, but the Senate appropriations committee has just announced full funding for the Webb telescope!!

  • Jonathan Livengood

    Someone should maintain a public, searchable database of predictions made by so-called experts in various fields. The label “expert” could then be reserved for people who routinely make accurate predictions in their area(s) of expertise. This would also give some teeth to the idea that expert opinion has some evidential value — what experts say would (by definition) be statistically associated with what actually happens in the world.

  • Robert

    Mainstream economists ignore in their teaching that what they teach has been shown to without empirical or logical foundation decades ago.

    For example, behavioral economists have shown agents are not utility maximizers. Many have replicated Hall and Hitch’s work showing the neoclassical theory of the firm to be false.

    The utility-maximizing agent exceeds a Turing machine in computational power. If one applies Arrow’s impossibility theorem to an individual agent, a reasonably-behaving agent need not have an utility function. In other words, agents need not behave “rationally”, under the neoclassical economists peculiar definition. Even if agents were rational, the Sonnenschein-Mantel-Debreu theorem shows that this has next to no empirical implications at the level of individual markets. The SMD theorem reinforces the similar conclusions of the Cambridge Capital Controversy. Markets can be expected to exhibit any dynamics you want, including chaos. No presumption exists in the theory that markets rapidly approach equilibrium.

    My comments above are about microeconomics. Some say macroeconomics is confused, but micro is fine. They are wrong and, at least, ignorant. But the above shows that macroeconomics cannot be microfounded in the way that both freshwater and many saltwater economists strive for. I am particularly amused by the widespread use of representative agents in neoclassical macroeconomics. This use is without logical support in microeconomics.

    Other approaches to macroeconomics are available, but ignored by mainstream macroeconomists. I mention, for example, the circuitist schools, structuralism (as practiced by, e.g., Lance Taylor), and stock-flow consistent models (as practiced by, e.g., Wynn Godley).

    It is hard to see how one can teach mainstream economics straight without being a liar. But mainstream economic education, through graduate school, seems to be a socialization into norms of ignorance and dishonesty.

  • Alan

    Here is one reason why economics experts are not to be trusted.

    The title, “Notes on Sex, Adventure, Monomaniacal Sociopathy and the True Function of Economics” promises a great read, and it is.

  • kitov

    Actually, I do not like the term “expert”. When I hear it I usually see a round table with several people (called experts) discussing a problem without any solution in scientific terms. As a rule, they can explain any process or phenomena with the same words and arguments they used to explain the opposite process and phenomena. For me its enough to decide that they are worth nothing together with their words. Economic “experts” use a very limited agrument base to explain everything.

    A researcher in the hard sciences is hardly an expert explaining all observations and usually knows what s/he knows and what s/he does not know. The latter is the matter to investigate. When a researcher works as an expert and brings to the unprepared audience (almost any place except specialed seminars, workshops, conferences, etc.) some hypothesis with a large uncertainty it usually has a negative result. The best case, nobody understands and forgets.
    The worst case, politicians use one of many possibilities under the larger uncertainty for their dirty profit. As an example, I recall a long discussion in the USSR about the necessity to turn nothern rivers to the Caspian sea, which had been losing water and thus area before the 1970s. The reason is clear – money and resources, i.e. power, and this project was supported by many “experts” who forecasted the sea to disapper according to their linear models. The government was ready to start. However, for an inner lake oscillations is a natural regime (as was argued by many scientists, chiefly, physicists) and the Caspian see has been growing since the 1970s and has inundated many small villages. Hence, do not give any chance to politicians to use your knowledge in their interests. In other words, do not be “experts”. (In reality, it was not the strong scientific opinion but the disintegration of the Soviet Union that stopped the project. Nobody is able to stop the greater political project “global warming”.)

  • spyder

    Perhaps we could take a page from Garret Keizer:

    “Like a war-wounded veteran unable to give his full trust to anyone who has never experienced the traumas of combat, I can find it hard to respect the opinions of anyone who has never taught school—not only in matters of education, which is reasonable enough, but also in matters of philosophy and politics. John Adams, Samuel Johnson, and Henry David Thoreau, to name but three who make the cut, tried their hand at “school mastering.” All three proved more or less dismal at it; all had greater things to do in their lives than I, whose best accomplishments have arguably taken place in a classroom. Still, I attribute the lack of illusion in their thought, their disinclination to dogma on the one hand and despair on the other, to the fact that they were tested as teachers. They had encountered humanity in all its rawness and variety, and with the dubious aim of “forming” it in some way. In the process, they had beheld their own selves as naked as a human being can get, and may in fact have achieved greatness partly out of fear of being that naked again.”

    Physicists and economists have their own philosophies and politics (and their own views on education). We need to seek to achieve a reasonable degree of respect, and perhaps more for those with whom we agree,

  • John Merryman

    In economics, I think one of the primary misconceptions is of assuming capital is a commodity, due to its relationships with such. The reality is that it is a contract. A commodity is subject to the law of supply and demand and since there is no material limit to the supply of capital, it is demand which sets the limits. So it becomes imperative for the financial system to keep increasing demand. Thus ever lower loan standards, pushing ever more debt into both the private and public sectors and when all else fails, legitimizing wagering as a financial necessity, since effectively endless amounts of capital can be juggled. Which is why we have derivatives markets many times the size of the economy on which they are based.
    The fact though, is that as a contract, money is a promise and ultimately only as much can be promised as can be delivered.
    This first occurred to me some decades ago, trying to figure out how Volcker cured inflation by raising interest rates. Inflation is primarily due to an oversupply of capital, but in drawing down this oversupply, by constraining the growth of the money supply and reducing it by selling Treasury bonds held by the Fed, interest rates rose dramatically. This higher cost seriously inhibited demand for capital, ie. borrowing. So how did they reduce the oversupply, when their methods also reduced demand? It just so happened that by the last time Volcker started to lower interest rates, 1982, the Federal deficit, under Reagan, had reached 200 billion. Which was real money in those days. So, I ask you, what is the effective difference between the Fed selling debt it is holding and the Treasury issuing fresh debt?
    For one thing, the Treasury sells far more than the Fed can and the money it collects isn’t just stored, with interest paid to those who own this excess, but is spent back into the economy in ways which enables/encourages further private sector investment, rather than competing with it, thus having a multiplier effect on the demand for capital.
    One would think for an economist, this would seem fairly obvious, but when you think about it, it’s not a point which too many wealthy people want emphasized, that they need debtors to maintain the value of their wealth, and would pay economists to espouse, since most economists are employed in the financial and corporate sectors, as well as by schools funded by them.
    It’s the simple physics of organization that those who support a system will be promoted by it and those who question it will be sidelined. The feedback loop creates bubbles and the larger they are, the more difficult it becomes to recognize and regulate them. I sometimes wonder if there are any such feedback loops in the hard sciences. Multiverses anyone?

  • spyder

    From David Graeber, from the blog Naked Capitalism:

    Murphy argues that the fact that there are no documented cases of barter economies doesn’t matter, because all that is really required is for there to have been some period of history, however brief, where barter was widespread for money to have emerged. This is about the weakest argument one can possibly make. Remember, economists originally predicted all (100%) non-monetary economies would operate through barter. The actual figure of observable cases is 0%. Economists claim to be scientists. Normally, when a scientist’s premises produce such spectacularly non-predictive results, the scientist begins working on a new set of premises. Saying “but can you prove it didn’t happen sometime long long ago where there are no records?” is a classic example of special pleading. In fact, I can’t prove it didn’t. I also can’t prove that money wasn’t introduced by little green men from Mars in a similar unknown period of history.

  • Patrick Powers

    “Why do we — or should we — accept the judgements of natural scientists more readily than those of social scientists?”

    Well, I don’t see such a thing generally occurring.

    Some people are anti-science and don’t accept either. Enough about that.

    Some are pro-science and trust the system. Boring.

    So by “we” I conclude he means people who work in universities and colleges.

    Well, I have a master’s in statistics and can tell you I saw economics as a corrupt discipline. Every week I saw obviously absurd economic theories promoted in the media. These theories had in common that their application would be to the advantage of the rich.

    I recall the Hoover Institute, a building constructed on the Stanford campus and occupied by economists. Obviously a good deal of money had been given to the university, and I expected that the quid pro pro would be research papers favorable to the donor with the Stanford seal of approval.

    I quite like classical economics up to about 1950, when economists seemed to have contracted chronic math envy. They set up highly unrealistic assumptions so that mathematical tools could be applied. Perhaps the goal was to impress and baffle the rubes. Somehow these fabulous assumptions came to be mistaken for social reality. Don’t ask me how.

    Quite often bogus statistical errors were made to justify harmful economic practices. There was Long Term Capital Management, which crashed with great losses when it was foolishly assumed that losses were uncorrelated. This was the first big bailout. Many more followed, steadily increasing in size until TARP. It appears that nothing was learned. Perhaps no one cared to learn. Why should they learn? They are making a ton of money doing it the wrong way. Wrong for us, right for them.

    All this greatly darkens the reputation of economics. Physics has nothing like this, at least until recently with the absurd lies about scientists trying to get rich off of bogus global warming data. But if Jill Voter has never met a scientist in her life, why should she think this is absurd? For all she knows climatologists hold drunken orgies where they fantasize about haw they are going to blow the loot once the scam catches on bigtime.

    On the other hand, there are still economists of integrity and reputation who avoid these problems and use mathematics appropriately. However their voices are often unheeded, and economics continues to labor under a cloud.

    Recently in biology one sees similar corruption. The crooked scientist comes up with the results a drug company wants. If there is money to be made through lying, someone will take it.

    Physical vs. social science has nothing to do with it. If there were big money to be made off of Big Bang theories or the half-life of the proton, then physics would have the same problems. In sum, in life I have learned to completely disregard all statements made by anyone who has a personal financial interest in the topic at hand. Since this covers a solid majority of pubic (mis)information, this does wonders to dispel confusion.

    “when should, in completely general terms, a non-expert simply place trust in the judgment of an expert?” I think it is obvious that in this modern world we have no choice other than to put some trust into others. I can’t personally verify all human knowledge. I can’t fly all over the world to check the accuracy of reportage. I can’t expect to be present at the birth of the future President. I’m a scientist myself so while it has its fads, phobias, mistakes, and blind spots I generally trust that system. What better game is there?

    I have faith in institutions and individuals with a reputation for truth, because they have a great deal to lose by lying or being mistaken. But if someone thinks The Wall Street Journal or Rush Limbaugh or some anonymous Internet source has a reputation for truth, there isn’t much if anything I can do about it. It’s a free country. All in all, people generally believe whatever they feel like believing.

    “So my advice to economists who want more respect from the outside world would be: make it much more clear to the non-expert public that you have a reliable, agreed-upon set of non-obvious discoveries that your field has made about the world. People have tried to lay out such discoveries, of course — but upon closer inspection they don’t quite measure up to Newton’s Laws in terms of reliability and usefulness.”

    Let’s compare Newton’s Law with Adam Smith’s free markets. I would say that now that Communism has bitten the dust that world belief in these ideas is about equal, and many would say Smith’s was more useful. As for physics, just how useful is string theory? CERN? Superfluids? Cosmology? Economists have plenty of ideas that are useful, their problem is that some very powerful people consider it more desirable for wrong ideas to be believed. Physics is now getting a taste of this as well. Not so yummy, hmmm?

  • John Merryman

    It would seem part of the problem is that money is assumed to be a substitute or notational commodity, but it is really a substitute for trust. A homogenous and organic community doesn’t need some reductionistic form of economic contract, as the basis of such societies is a wholistic trust and personal knowledge. So it would be counterproductive to have a manufactured substitute.
    Money only becomes necessary when different groups interact and communities grow too large to know all or most of the other members. Then some common currency becomes necessary.
    Money, as a multiparty contract, actually functions as a form of public commons, much like a road system. We own our houses, cars, businesses, etc, but not the roads connecting them and very few people cry socialism over that. If people understood money as public property and society treated it as such, people would be much more careful what value they convert to money and tend to develop those more organic networks and natural stores of value again.

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  • John Merryman

    “As a citizen I am interested in the stakes of this controversy, perhaps more so than economists. I want voices that I can trust in the dust of factious debate. I want my taxes to pay for their independence and public service. But as an historian my intuition is that these wishes are both naïve and quaint. The professoriate’s extramural commitments are no longer an exception, liable to policing and containment. To open the University was the banner of the labour economist and super-President of the University of California, Clark Kerr, but also of the Free Universities that antagonized his vision. The outcome matched neither design. We have neither the “Multiversity” nor the politically engaged professor, we have an entrepreneur scholar of uncertain loyalties.”

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  • Brian Too

    The problem is one of complexity.

    In physics you can plausibly isolate systems. In the more complex sciences (complex may not be the right word, I’m liable to make someone react badly, but I cannot think of a better word at the moment), you hit more and more barriers to doing so. How many isolated economies are there? In the past there were a few but now?

    In the more fundamental sciences (ah that’s better) you can therefore test alternate hypotheses with controls. How do you do that in economics?

    We say that Hoover’s policies were a failure during the Great Depression, and Roosevelt’s were a success. OK, that’s true on the face of it. But how do we control for the passage of time and numerous other factors? Maybe Roosevelt would have been a failure in Hoover’s day, and vice versa. I’m no historian and undoubtedly many will point out my example’s failings, without noticing the larger point I’m making.

    How do the social scientists perform a proper A-B test and prove, beyond any doubt, which scenario is the truth? There are so many uncontrolled variables it is difficult to make any point with mathematical certainty.

    I sometimes feel that the difference between a successful social policy and an unsuccessful one is not so much how correct your fundamentals are, but how many people you can rally to your side. In sufficient numbers you can overwhelm a mediocre efficiency in your policy. Just throw more resources at the problem.

    The academics have another problem. They desperately want to be relevant to the real world, and money is a powerful lure. Lots of economists have, it seems to me, overstated their actual predictive abilities.

    On the other side of the fence the money people don’t care about academics. They look for any advantage, even if it is only 5-10%. Problem is, if they start making money and credit the academic theory for those gains, it becomes easy to over-ascribe the success to academic underpinnings. Even the reverse is true (monetary loss /= totally worthless academic knowledge).

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  • James Ph. Kotsybar

    — James Ph. Kotsybar

    When the general public hears about
    A breakthrough in scientific research
    They want to add their voices to the shout,
    So as not to feel they’re left in the lurch.
    That they have opinions, there is no doubt.

    They’ll foist themselves into the dialogue,
    When something sensational’s put in print.
    Though their comments reveal they’re in a fog
    Without having the slightest clue or hint,
    It won’t prevent them posting to the blog.

    Most often, all they can add is their moan:
    “Why can’t science leave well-enough alone?”

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  • Anthony

    Professor, I would love to see yourself and Prof. Hanson discuss this topic on

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Cosmic Variance

Random samplings from a universe of ideas.

About Sean Carroll

Sean Carroll is a Senior Research Associate in the Department of Physics at the California Institute of Technology. His research interests include theoretical aspects of cosmology, field theory, and gravitation. His most recent book is The Particle at the End of the Universe, about the Large Hadron Collider and the search for the Higgs boson. Here are some of his favorite blog posts, home page, and email: carroll [at] .


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