Taking Models Too Literally

At Cafe Hayek, Don Boudreaux points us to a wise quote from Milton Friedman.  Below is a comment I left on that post, expanded:


In the highly stylized world of models, where information is perfect, markets are costless, where all preferences are known, where government is costless, and things never change, it is trivially easy to come up with exceptions to free trade and free enterprise. Shift a curve here, refuse to count costs there, and boom! a theoretical reason why tariffs or export subsidies can be beneficial.

However, when those stylized assumptions are relaxed, in other words in a more realistic world where information is imperfect, markets have transaction costs, where preferences are revealed, where governments have administration and operation costs, and where things change, these theoretical reasons disappear like a shadow in the sun. Conversely, the case for unilateral free trade becomes stronger, since it is not dependent upon those assumptions the way the other theoretical cases are; free trade is formulated under those assumptions, yes, but it is robust to movements away. Things like optimal tariffs are formulated under those assumptions but are not robust to movements away from those assumptions.

The true test of any theory is not how well it holds up in perfect conditions, or how well does it perform in the circumstances in which it was conceived, but how robust it is to movements away from those idealized conditions.  Economists from Adam Smith to Harold Demsetz and beyond have warned us against these nirvana fallacies.  True knowledge is gained when we stress-test our models and see how robust they are.  Testing this robustness gave us such fields as Public Choice, Law & Economics, Political Economy, Money and Banking, and the like.

Economic models serve a purpose: they are ways of thinking, methods of analyzing phenomena. However, they are not descriptive of reality. They were never meant to be. When basing policy off of those models, the policy-proponents are making a grave mistake: they are moving their models away from the abstract and into the descriptive. In other words, they are taking their models too literally. This literal interpretation of models can be extremely dangerous.

Hard Coase, Soft Coase

Over the course of this semester, I have been working on two research projects which parallel each other very closely.  Both look at water market exchanges (ie, people who buy and sell water), one from a Coasian perspective (ie, how changes in legislation affect markets), and the other from an Ostrom/Ellickson perspective (ie, how social norms and mores affect markets).  Both these papers are being finished up and I will post links to them here, but there is an interesting connection between the two: both forms of bargaining are “bargaining under the shadow of the law.”

“Bargaining under the shadow of the law” typically refers to working within a framework established by a court (eg, how a court determines property rights).  This is the “hard Coase” theorem.  However, “law” need not apply to just courts; indeed, it does not.  There are general rules, or laws, that develop “[From] our continual observations upon the conduct of others,” to help us “form to ourselves certain general rules concerning what is fit and proper either to be done or to be avoided,” (Adam Smith, The Theory of Moral Sentiments, Section III, Chapter IV, Paragraph 9).  These rules are the social norms and customs, what the Romans called mos, or “a guiding rule of life” (see On Duty by Cicero, translated by Benjamin Newton, specifically Newton’s glossary at the end of the book).  These rules, customs, laws govern our behavior and our interactions just as much as legislation does (perhaps even more so) since we face not jail or prison if we violate these rules, but censure, disapprobation, and demerit from our fellow man; extreme cases could result in isolation from the community, a terrible punishment, indeed, given that man is a social creature.  It is these rules, this law, that I refer to as “soft Coase.”

In both the hard Coase and the soft Coase situations, Coase’s arguments about bargaining hold generally true: changes in the law affect how we behave and interact with one another.  This, in turn, affects how we address externalities and other economic behavior.

The Coase/Ostrom/Ellickson look at collective behavior, sprinkled liberally with Alchian/Demsetz insight and Tulluck/Buchanan public choice theory, is an important way of exploring the market process.

The Problem with Optimal

In economics, the concept of “optimal” is often used: optimal taxation, optimal pollution, optimal consumption, etc.  Optimal, in an economic sense, just means marginal benefit equals marginal cost.  For individual actors, such a definition and usage makes sense.  However, problems arise when trying to generalize optimality over collective units.

With optimality, it is important to remember a key characteristic about benefits and costs: they are subjective.  All value, whether a benefit or a cost, is subjective.  Therefore, an individual can optimize his behavior by aligning his subjective marginal benefits and subjective marginal costs.  But this is not true with collective action.  When analyzing collective action, the point of view of the analyzing person comes into play.  Collective agencies cannot have subjective feelings about things, they cannot optimize; the one who does the analysis optimizes based on his/her subjective values.

Therefore, it doesn’t make sense to talk about the optimization of collective units in the same way it does to talk about the optimization of individual units.  Concepts like “optimal tariffs,” “optimal taxation,” etc., lose their meaning when we start considering subjective costs.  It comes down very heavily to the subjectivity of the person who is doing the calculating, what he/she believes the costs/benefits are.  When that individual is responsible (ie, they pay the cost if they are incorrect) for the results of their actions (eg, the owner of a firm), then such subjectivity is not an issue; they are properly incentivized to make sure their subjective understanding aligns with their collective goal.  When the person is not responsible (eg, government agents), then such optimization becomes…problematic.

The Hayek Memorial Pathway


The picture above is what I like to call the Hayek Memorial Pathway located on GMU’s Fairfax campus.  This pathway is the result of thousands of students deciding to go the shortest path rather than the long paved path.  In other words, this path is a spontaneous order; the result of human action but no one person planned such a path.


At Cafe Hayek, Don Boudreaux has a blog post discussing the rather frequent argument used by some protectionists who object to foreigners owning American assets.  Don writes:

One of the facts that I pointed out [in Don’s recent debate with Ian Fletcher] is that a U.S. trade deficit is good for the U.S. insofar as such a deficit means that capital is flowing into the U.S. and creates new businesses (or bolsters existing businesses).  Think, for example, of BMW’s factory in Greer, South Carolina, or of any of the many Ikea stores across the United States.

In reply, Fletcher agreed that such investment is productive, and even that it’s beneficial for Americans.  “However,” he replied (and here I quote from memory), “it would be even better if those assets were owned by Americans.”

The core error in Fletcher’s reply is the assumption that the productive assets that are brought into being by foreign investment would exist in the absence of foreign investment.  Fletcher assumes, for example, that the successful Ikea store in Dale City, Virginia, would exist in the absence of Ikea’s decision to build and operate a store there.  Fletcher assumes, in other words, that the ownership of an asset is economically distinct from the creation of an asset.  But this assumption is plainly mistaken.  Nothing prevented Americans from building a large furniture (or other kind of) store on that very location before Ikea built its store there – nothing, that is, other than the failure of any Americans to have the vision or the willingness to do so.  Ikea’s entrepreneurial vision and willingness to take the risk of building a store in Dale City added tothe capital stock in America (and in the world).

To build upon Don’s point:

People like Fletcher treat assets and resources as if they are mana from Heaven, that these factories and stores and the like just fall to the Earth, waiting to be claimed by whoever walks by.  But goods and services are brought into existence and traded through human action. It’s man, not God, that transforms and produces. God just gave us the faculties to do so.

However, there is also a crucial element of what Israel Kirzner called “surprise” needed.  That is, being aware when an opportunity presents itself.  Allow me to explain via metaphor:

Two shoe salesmen land in a foreign country. Both notice no one in this country wears shoes. The first calls back to headquarters: “I’m headed home. There are no sales opportunities here. No one wears shoes!” The second calls back to headquarters: “Send me more people. There are lots of sales opportunities here. No one wears shoes!”

The point of this story is that entrepreneurial activity includes “surprise,” that is: being aware of an opportunity that presents itself even when not actively searching for it.  One of the salesmen, the one who thought no opportunity existed, had no such element of surprise.  The other did.

There’s no reason to assume that if Ikea hadn’t shown up, someone else would have. This isn’t a “search cost” thing (ie, other people did not simply look hard enough and Ikea just looked harder/longer), but rather an entrepreneurial surprise thing. Ikea spotted an opportunity and invested. It’s probable no one else would have spotted (or, at least spotted at the same time) this opportunity.

But let’s say more. Let’s say that some American firm did spot the same opportunity at the same time and were competing against Ikea for the same resources (land, labor, etc). Would it be safe to say that the community would be better off if the assets were owned by the American firm rather than Ikea? Not necessarily. Given that Ikea won the bidding war, that probably means Ikea had a higher value on the resources than the other firm. This, in turn, means that Ikea can likely produce more value out of the resource, which means providing value to the consumers of furniture. By being more efficient (that is, using fewer inputs to achieve the same or greater outputs), Ikea produces more value for the community than the other firm that lost the bid.

Economic growth occurs through the mechanisms of discovery and surprise (a la Kirzner) and resources going to their most valued uses.  We cannot take for granted either one of these processes.

Flaws of GDP when Discussing International Trade

Gross Domestic Product, better known by its acronym GDP, is frequently cited and understood by non-economists as the measurement of the economy.  But GDP is not the measure of the economy, it’s a proxy measurement for economic activity (creating a measurement for the economy is problematic because the economy is not something that can be measured in its entirety.  Its the grand sum of all human actions, some of which are measurable and observable and some of which are not).

One of the most commonly known things about GDP by non-economists is its accounting formula:

GDP=Consumption (C)+Investment (I)+Government Expenditures (G)+Net Exports (NX), with Net Exports being defined as the difference between imports and exports (Exports-Imports).

It is on this Net Exports figure I will focus the conversation as it is from whence the confusion about the effects of international trade on economic activity comes from.

Often in news reports, we will see a report along the lines of this:

US economy grows 3.0 percent in third-quarter  

The U.S. economy unexpectedly maintained a brisk pace of growth in the third quarter as an increase in inventory investment and a smaller trade deficit offset a hurricane-related slowdown in consumer spending and a decline in construction.

Exports increased at a 2.3 percent rate in the third quarter, while imports fell at a 0.8 percent pace. That left a smaller trade deficit, leading to trade adding 0.41 percentage point to GDP growth.  (Source)

However, this reporting, which states that the trade deficit affects GDP which leads many non-economists to the conclusion that international trade and imports are bad for the economy, is incorrect.  it is based off a misunderstanding of the GDP calculations.  To explain why, we need to understand exactly what GDP is:

GDP stands for Gross Domestic Product.  “Domestic” is the key word there.  We’re focusing on consumption, investment, government expenditures, and exports of domestically produced goods.  So, why are imports in the equation at all?  Why not just simply sum all the consumptions, investment, government expenditures, and exports of domestically produced goods?  Simple: we don’t know what proportion of these components contained imports and what proportion contained domestic goods.  But we do know how many goods/services were imported.  So, we can simply subtract out the imports from the equation to give us the true GDP factor.  In other words, imports are an adjustment factor, not a component of GDP!  Without the import adjustment factor, we’d be overestimating GDP.

I think a simple numerical example will help explain:

For the sake of simplicity, assume a closed economy (no international trade) and only one type of activity, Consumption.  Thus:


Since all goods are produced domestically, we can say:

GDP=Cd, where Cd stands for Consumption of domestically produced goods/services.

Assume Cd=5.

Thus: GDP = Cd, GDP = 5.

Now, assume the economy opens and only imports (that is, they have a trade deficit).  GDP is now:

GDP=C-Imports (I).  However, C = Cd+Ci, with Ci defined as consumption of imported goods.

Let’s say imports = 6.

Our GDP formula is GDP=C-I.

Rewritten: GDP = Cd+Ci-I

GDP = 5+6-6

GDP = 5.

As we can see here, once we adjust for imports (which is necessary because we’re dealing with gross domestic product), GDP does not change because of the trade deficit!  It is incorrect to say that imports reduce GDP, QED.

To be clear, there may be secondary effects imports have on GDP (say, for example, imports drive out domestic producers, which can reduce Cd, which can reduce GDP), but it is not a given that imports reduce, as I have shown here.  But even then, it is not necessarily a bad thing if GDP falls because of more imports.  GDP is a proxy, not a measurement, of economic activity and well-being.  If one is made better off by buying imported goods rather than domestic goods, then that will not show up in GDP, but it is a real gain nonetheless (for an explanation of this point, see the previous posts in this series).

Update: Here is Pierre Lemieux on this very same topic.

International Trade

The previous blog posts have discussed how trade benefits the traders.  We began with the observation that people act purposefully.  Then, we developed that observation to answer the question “why do people trade” and found that people trade because such a transaction is mutually beneficial.  That led us to a graphical representation of the question: the supply and demand diagram.  Finally, we were able to show the gains of trade that occurred.  At the end of this blog post, we touched on the claim that these gains from trade do not depend on the geographic or political location of these actors (gains from trade do not change whether the trade is inter-neighborhood, inter-town, inter-state, or inter-national).  I will now expand on that point.

Trade occurs because both parties benefit and thus gains from trade are realized.  The gains may not always be exactly perfectly realized the way they are depicted in the supply and demand model, but it is a very accurate representation of the economic gains.  Given the sheer repetition of human action and competition of buyers with buyers and sellers with sellers, gains will tend to be maximized.  If Joe values apples more highly than Sally, Jow can bid away Sally’s apples; he can offer her some kind of compensation to part with her apples.  Likewise, if Sally is competing with Brian to sell Joe apples, and Brian values his apples less than Sally (ie, he charges a lower price), then Brian can bid away Joe from Sally.  Brian views what Joe offers as more valuable than both apples, and more valuable than the value Sally puts on her apples, so there are gains from trade (apples moved from their least valued use to their more valued use).

Gains from trade hold in an international setting, too.  One of the chief objections put forth by protectionists scarcityists is that international trade is one-sided and that all the benefits accrue to just domestic consumers and foreign sellers.  Therefore, it is only the foreigners who pay the price for tariffs, and tariffs can result in a higher net benefit.  Absent some heroic assumptions, this cannot hold true.  Why?  Because of gains from trade!  If the gains to domestic producers were able to offset losses to domestic consumers, then domestic producers could simply bid away the domestic consumers from the foreign competitors.  Consider Joe, Sally, and Brian again.  Joe and Sally are both citizens of Motonia and Brian is from Hogeland.  If Joe buys apples from Brian, then Brian offers him the best deal.  However, if Sally can offer Joe a better deal, then she can simply bid away Joe’s business from Brian by willing to charge Joe a lower price.  You would get a higher net benefit by this action.  If Sally is unwilling to bid away business, then we can conclude her gains would not offset Joe’s losses, and the total surplus would shrink compared to trade with Brian.  From a net benefit perspective, international trade does not matter (nota bene: this same logic holds if we adjust the scarcityist claim and they try to make it an externality argument, that Sally’s job loss makes things a net benefit.  See the Coase Theorem).

There are other scarcityist arguments against free trade that I will not address here; they tend to be political or legal in nature, and that is beyond the scope of these blog posts.

Here ends the substance of this series on trade.  The next post will discuss trade and GDP, highlighting some of the flaws of GDP and why how it is currently understood by most non-economists is incorrect.  The following post will be a recap of all I have written.