Posts Tagged Comparative Advantage

Article on Pieria: The Politics of Trade

I have an article on the site Pieria, arguing something I have argued before, but this time from an international perspective:

The reality of trade is that it is always, necessarily, regulated. There is no ‘free’ baseline, untouched by politics, history and culture, to which we can aspire. There are merely a series of political decisions, special interests and historical accidents, some of which are hidden, some of which are less so, but all of which have very real impacts on trade and specialisation

The article (naturally) contains an attack on comparative advantage:

However, although comparative advantage is – in the words of Paul Krugman – something of an “economist’s creed”, its relevance as a theory is incredibly limited: in fact, it has long been acknowledged that the theory explains a relatively small amount of international trade.

and goes on to argue for Bretton-Woods style institutions.

Obviously I’m not the first person to make these arguments (Chang and Rodrik spring to mind), but sometimes I worry those on the side of ‘protectionism’, which I’d broadly align with, get sucked into caricature arguments similar to those of their ‘free trade’ opponents. What we really need is an institutional perspective on development and trade.


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Is Economics A Gun That Only Fires Left?

Sometimes it seems like economist’s pet principles are applied selectively, in such a way that they attack ideas generally endorsed by the left end of the political spectrum. This isn’t to say economists themselves are ideologically inclined toward any opinion; merely, that key aspects of their own framework, and the way they present these aspects, lends itself to a more ‘right-friendly’ way of thinking.

In part, the issue is merely one of a disparity between how economists present issues to the public and how they speak to others in academia. Dani Rodrik noted this issue in his book The Globalisation Paradox. Here he describes a situation where a reporter asks an economist whether free trade is beneficial:

We can be fairly certain about the kind of response [the reporter] will get: “Oh yes, free trade is a great idea,” the economist will immediately say, possibly adding: “And those who are opposed to it either do not understand the principle of comparative advantage, or they represent the selfish interests of certain lobbies (such as labor unions).”

Rodrik then contrasts this with how such a question would be answered in the classroom:

Let [the student] pose the same question to the instructor: Is free trade good? I doubt that the question will be answered as quickly and succinctly this time around. The professor is in fact likely to be stymied and confused by the question. “What do you mean by ‘good’?” she may ask. “Good for whom?… As we will see later in this course, in most of our models free trade makes some groups better off and others worse off… But under certain conditions, and assuming we can tax the beneficiaries and compensate the losers, freer trade has the potential to increase everyone’s well-being…”

This adherence to basic, market-friendly principles over nuance can be found often in ‘pop’ economics: for example, economist Paul Krugman does it in his book Peddling Prosperity. The book is intended as an survey of nonsensical ideas from both the left and the right, remedying them both with a cold hard dose of facts, plus some basic economics. However, Krugman treats the left and right somewhat asymmetrically: with the right, he primarily opts for facts, whereas with the left, he uses economic principles

This is quite possibly because the right’s arguments, though they are taken to an extreme, have economic principles on their side, while the left’s do not. The ‘supply side’ economics that Krugman takes issue with is really just an extreme statement of the well known principle of deadweight loss, which suggests that taxes decrease output. If taxes reduce output by enough, then it logically follows that not only output, but overall revenues might fall if we raise taxes. Krugman would not question the principle, so he spends several chapters documenting evidence against the idea*.

Krugman then follows this up with a section berating the ‘strategic traders’, endorsed by Bill Clinton and others on the centre-left. Strategic trade suggested a role for government policy in promoting industry, because various clustering effects, economies of scale and positive feedback loops could mean that the initial wave of government investment could kick start an industry. As Krugman himself notes, such dynamic effects and ‘historical path dependence’ could render comparative advantage obsolete, since comparative advantage posits a more fundamental, innate reason a country produces a particular good, one that cannot be changed with policy (one that may be more applicable to agriculture).

Yet, in contrast with his section aimed at refuting the right, Krugman offers scant evidence suggesting government intervention doesn’t work. Instead, he effectively restates the theory of comparative advantage, coupled with a typical story to illustrate it. This is despite explicitly suggesting it might not be applicable in the previous chapter. When pushed, Krugman is prepared to fall back on his pro-market principles, even in areas where he knows they may not apply.

William Easterly does something similar in his book The Elusive Quest for Growth. The book is a survey of various policies than have purported to be panaceas for development, such as education, investment and population control. (As you can see, economists really love writing their “I’m an economist, here’s how it is” manifestos). Easterly finds every supposed development panacea wanting based on the available evidence, which is fine. However, occasionally he supplements his arguments with an excruciating example of ‘economic logic’ that always looks out of place.

For example, in the section on increasing availability of condoms, Easterly essentially makes the argument ‘how could people be lacking condoms? If they were, the free market would provide them!’ I am reminded of the joke about the economist who does not pick up a £10 note from the ground, because, if it were really there, somebody would already have picked it up. Easterly is a smart guy with a lot of concern for the poor, and I have a hard time believing he wouldn’t agree that a country might lack the institutions to deliver condoms, that people might lack the education to know why they’d need them, that it might conflict with their beliefs, etc. But the ease with which he can apply a pet economic principle is just too tempting, so he ignores these factors.

Another example is where Easterly asserts that population growth cannot be a problem, because “an additional person is a potential profit opportunity for a person that hires him or her” and as a result “the real wage will adjust until the demand for workers equals the supply.” It’s quite clear things don’t function this smoothly in labour markets even in developed countries; for theoretical reasons as to why, Easterly need look no further than John Maynard Keynes; failing that, modern work on labour market frictions might prove sufficient. Again we see a neat but overly simplistic principle applied when even the economist themselves surely knows better.

So it is not uncommon for economists to prefer their more ‘free market’ principles over nuance when writing for a popular audience**. But is this problem only limited to popular economics? Economists seem to think so; to them, the issue is primarily one of communication, and knowing the limits of your models. This is fine as it goes. However, there are reasons to believe this bias extends into the murky depths of academia.

In my opinion, there is one major culprit of selective application in economics, and it is one that cannot be explained by economists simplifying their work for public consumption: the Lucas Critique. The Lucas Critique suggests that adjusting policy based on observed empirical relationships from the past will alter the conditions under which these observations were generated, hence rendering the relationship obsolete.

Unfortunately, in practice, Lucas’ version of the critique seems to have been used to beat ‘Keynesians’ over the head, rather than being universally applied as a tool to further understanding. To illustrate this, here are some areas I think Lucas critique-style thinking could be applied, but hasn’t:

  • Milton Friedman’s methodology. If a ‘black box’ theory corroborates well with past evidence but we aren’t entirely sure the internal mechanics are accurate, there’s no reason to believe the corroboration will hold, or to know how the mechanics of the system will change, if we change policy.
  • Nominal GDP Targeting (NGDPT). This hasn’t caught on much on the left (in my opinion, for primarily ideological reasons: it’s anti-Keynesian, it partly absolves the private sector of responsibility for recessions). But it doesn’t seem to have occurred to proponents of NGDPT that we must ask if the relationship between inflation, RGDP and NGDP will break down if we try to exploit it for policy purposes. This is despite the fact that we are talking about precisely the same variables as  the Phillips Curve, the primary theory to which the Lucas Critique was initially applied.
  • The supposed “deep parameters” of human behaviour on which Lucas suggests we construct economic models, such as technology and preferences. For a neoclassical economist, you are born with a set of preferences and you die with them, while in many models technology is a vaguely defined exogenous parameter. Yet a single example can show that both of these things can change with policy: government investment, which is at the root of a large number of technological break throughs. These break throughs have often resulted in new products, creating preferences that otherwise wouldn’t have existed. A model with fixed, exogenous parameters for technology and preferences is therefore hugely fallible to policy changes.

The fact that the critique hasn’t been applied to these examples leads me to believe it’s often only used to preserve existing economic theory.  In fact, the critique itself is really just a narrow version of the more general principle of reflexivity, noted by many before. Reflexivity is an ever-present problem that suggests an evolving relationship between policy and theory, not a principle that means we can fall back on economist’s preferred methods.

Is the Lucas Critique the only culprit? Well, I’ve found economists are generally critical of the assumptions and mechanics of heterodox models, despite appealing to Friedmanite arguments when questioned about their own. I’ve also found economists (okay, one) appeal to how businessmen really behave when defending their theories despite not paying much credence to alternative theories based on the same principle, such as cost-plus pricing. So maybe economists need to air out their theories and principles a bit, rather than simply applying them where it suits them.

Economist’s simple stories often capture some truths, which is why they will defend them to the death. But too often this becomes a matter of protecting a core set of beliefs, and being unwilling to apply them in new ways or even abandon them altogether. So economists end up deferring to their framework when it isn’t appropriate, or only interpreting it in their preferred way, particularly when they communicate their ideas to the public. The result can be that misleading conclusions about the economy remain prominent, even when economist’s own frameworks, interpreted completely, don’t necessarily imply them. Perhaps if economists were more willing to open up their theories, which can sometimes feel like something of a black box, these misinterpretations would be exposed.

*I won’t delve into the evidence here because it’s not the point, but you can easily find Krugman making the same arguments on his blog if you’re curious.

**In fairness to Krugman and Easterly, these books were written a while ago, and I’m sure they have updated their positions since then. I only wish to show that economists use this tactic, not that any one economist endorses any particular position.

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Are Static Neoclassical Models Useless?

If somebody presented you with a static snapshot of weather patterns, it would be clear that the model was fairly useless; as it didn’t capture dynamics, it would have nothing to tell you about the weather. Similar problems apply to neoclassical models: once you attempt to incorporate dynamic events, they don’t just become ‘wrong’, they become completely irrelevant.

Comparative Advantage

I posted recently about how CA is irrelevant for developing countries, but I’d like to expand: it is completely irrelevant for arguments about protectionism. The problem is that if you take into account the effects of tariffs on the productivity of the industries they are aimed at, it has nothing to say – not just for developing countries, but for any industry whatsoever. CA assumes that every country has an innate productive capacity in each industry that does not change over time. If you froze the world, CA might be a persuasive argument for free trade, but in a dynamic economy it completely irrelevant.


Say the price of a necessity goes up due to a supply shortage. Modelling this as a simple ‘price increase’ suggests that demand would go down. However, if people are expecting the supply shortage to continue or worsen, then isn’t it more probable that demand will go up? Mainstream economists might have an answer: the price increase can be modelled as a movement of the supply curve, whilst the new information about the supply shortage can be modelled as a movement of the demand curve:

(D1 to D3, S1 to S2)

Problem solved. Except this movement of the demand curve leads to a higher price, which in turn would cause people to alter their expectations of the shortage, leading to another movement, and so forth. This may be a highly specific example, but it touches on a central Sraffian criticism of these models, which is that the curves cannot move independently; a change in one creates ripple effects that violate ceteris paribus. Thus, taking a picture of the state of them at any one time tells you as much as a photo of a moving train tells you its velocity.


Both ‘curves’ are partially derived from expectations – one from expectations of returns on investments, and one from expectations of future needs for liquidity. Therefore, a similar criticism to Demand-Supply applies – movement of one curve alters expectations and so affects the other. This creates a feedback loop that simply cannot be captured by two intersecting curves. At any one moment, the diagram might be said to be ‘right’ (putting aside other objections), but this doesn’t mean it is useful.

I expect economists won’t appreciate a whistle-stop tour of their models that claims to have debunked them, but at the same time I expect they’d agree that the above ‘weather’ example would so obviously flawed that it would not need to be refuted formally. In order to avoid special pleading, economists will have to argue that the economy is at or close to equilibrium, rather than a dynamic system. I do hope nobody claims this after 2008 (or the recurrent crises for centuries before that).

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The Irrelevance of Comparative Advantage

Those advocating protectionist policies are often met with the stock response of ‘you don’t understand the principle of Comparative Advantage’. But it seems to me that economists haven’t put much thought into it themselves, as Comparative Advantage does not necessarily support free trade, particularly in developing countries. In fact, if you accept the ‘infant industry’ argument, it turns out Comparative Advantage has very little to say for developing countries or industry – it is irrelevant.

Perhaps a statement of Comparative Advantage is due. The idea is that every country should produce what it is most efficient at producing, regardless of what other countries produce – that is, each country should allocate its time as efficiently as possible based on its own strengths, resulting in maximum overall production. Trade barriers create extra costs and therefore inefficiency, which is undesirable.

Furthermore, a brief qualification of the ‘infant industry’ argument: as tariffs direct business to new industries by making them comparatively cheaper, they can develop brand loyalty, benefit from economies of scale and lower costs, gain expertise, establish contacts and trust with suppliers and distributors, and benefit from long term investments due to higher short term profits.

The problem is this: if by producing something, an industry can improve its long term ability to carry on producing it, Comparative Advantage becomes irrelevant in the short term. As with much of neoclassical economics, it is a static snapshot and does not capture dynamics like this. For example, if country A produces coke at 100 gallons a year and milk at 150 gallons a year, while country B produces coke at 50 gallons a year and milk at 25 gallons a year, Comparative Advantage is clear – A should produce milk and B should produce coke, even though A has an absolute advantage in both. This results in the highest net production possible.

However, what if country A’s coke industry and country B’s milk industry are new industries? And by producing milk, B can eventually up its milk yields to 200 gallons a year, whilst A could up its coke production to the same? Suddenly Comparative Advantage has nothing to say, and protecting these industries from competition as they develop seems like a good idea in the long run, both for individual countries and for net production as a whole.

The fact is that, as well as being compatible with one of neoclassical economist’s pet theories, extensive evidence supports the protectionism for development idea. Comparative advantage also has numerous other flaws in its applicability to free trade (one of which, the mobility of capital, was actually noted by Ricardo himself). Overall, it is not clear why it retains its status as some sort of irrefutable truth of the benefits of free trade, given that it actually has little to say about what trade policy should or shouldn’t be.

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