Why do economists who accept a theory oppose putting it into practice?  For example, I believe global warming is a rather significant problem.  I agree that it is internally consistent that carbon taxes (or some other variation like cap & trade) can reduce carbon emissions to a socially optimal level.  So, why then do I oppose carbon tax regulation?

There are many reasons why I (and many other GMU-style economists) oppose regulation even though a logical argument can be made, it could improve a given situation.  We tend to focus on public choice reasons (such as rent-seeking and agency capture).  The knowledge problem, most famously discussed by F.A. Hayek, is also often cited: government agents can too seldom possess all information and knowledge necessary to regulate desirably and much less “optimally.”

There is an element of the knowledge problem that warrants further attention, an element highlighted by Don Lavoie in his 1985 book National Economic Planning: What is Left? In this book, Lavoie greatly expands our understanding of the knowledge problem and its relevance for assessing central planning and more mundane government regulation.  He discusses Hayek’s formulation of knowledge as mostly tacit, but Lavoie also emphasizes that knowledge is built upon inarticulable foundations.  Attempts to articulate the inarticulate foundations are doomed to fail as each person carries with him or her different nuanced understandings of the language used in legislation authorizing regulations.

Consider, for example, the phrase “2+2=4.”  Understanding the phrase’s meaning requires a tacit, inarticulable understanding of the elements: 2, +, =, and 4.  If one were to try to rigorously define every element in that phrase, he would eventually fall into a problem of recursivity.  As children, when we first encounter mathematics, it may seem weird and arbitrary.  We just learn that 2+2=4 by rote.  It is only through repeated interactions with mathematics do we start to understand it.  To paraphrase the great mathematician John von Neumann, you never really learn mathematics.  You just get used to it.

The problem of inarticulable understandings of knowledge comes into play in the field of regulation.  The economist has a foundation of knowledge.  When he tries to convert that knowledge into policy, we run into a game of telephone.  At each step along the way, the knowledge and information get a little distorted. Each person has different foundations from which they understand the message the economist is delivering.  As such, the end policy would deviate considerably from theory, even if we assume away public choice issues.  In other words, the policy will look considerably different from the theory because of a sort-of language barrier.

Consider, for example, the word “cost” in economics.  We define “cost” to mean what one gives up to take a particular action (it is sometimes called “opportunity cost” for this reason).  Cost is inseparable from choice.  Yet, “cost” takes on a very different meaning for the general public, as it usually refers to a negative consequence (“the cost of reading is a headache”) or the monetary price of something (“the coffee cost me $2”).  Thus, the economist already faces a problem communicating his theory to policymakers.  But even within the field of economics, “cost” has different understandings.  James Buchanan’s excellent short 1969 book, Cost and Choice, discusses how “cost” has changed understandings among the various schools of thought.

I oppose regulation even when I understand the argument because argument and policy are not the same things.  When communicating, experts run into the telephone problem: the theory is misunderstood, misapplied, or miscommunicated.  Competition among experts helps solve these problems, yes, as experts become incentivized to be less wizardly and more like teachers.  But the knowledge problem remains, and regulation can only enhance the communication problems.