Economics is a branch of mathematics

Saw this post in the topic “What are the top 10 most popular economic myths?” and thought it worthy of a separate discussion.

Contrary to Mr. Olovetto, I argue economics IS a branch of mathematics, or at least, Praxeology is: In mathematics, you derive theorems from axioms. The thorems are true because the axioms are true. And the axioms are true either because they are self-evident or because they are assumed to be true by definition. Sound familiar?

It is often assumed Mathematics only deals with numbers and equations, but this is not so. Take Category Theory as an example. It is also untrue that anything which deals with numbers and equations must be mathematics, as I’m sure no one will assert Physics draws its conclusions by deriving theorems from axioms.

What are your thoughts on the subject?

That you’re not understanding the same thing as the poster is when they make that statement.

He was probably referring to the way mainstream economists love to fill their papers with meaningless, oversimplified equations. Though I thought the literal interpretation was still something interesting to think about.

Economics is a 3rd rate form of mathematics. The problem is people lean too much towards mathematics than the understanding of theory. If you don’t understand the theory, you’re lost.

Mathematics is a branch of computation. So is economics. They are not related otherwise.

I’m sorry, but this is a horribly deficient argument. Only because both mathematics and praxeology use deductive reasoning doesn’t make one a subset of the other.

Depends on what you call “mathematics.” Some say math is a subset of logic, others say logic is a subset of mathmatics. I’m of the latter group, but if you accept the former definition then you’re absolutely right.

My point is math and economics are more similar than some would like to acknowledge.

This. And I verify with my personal authority as a computer science undergraduate going to graduate school this Fall (post-graduation).

Who?

Agreed.

It’s a social science, not a branch of logic, math or epistemology. Get used to it.

Agreed. I don’t have time to say more now, but I will give you this passage from Rothbard:

And an engineer uses logic and so does a casher when they ring up green peppers and acknowledge that they are green peppers.

Yet simply because all people follow axioms in their actions and logically deduct the best route to the grocery store doesn’t mean all categories need to blur when analyzed.

I respectfully disagree. Economics is nowhere near a branch of mathematics. They are two separate entities. Even as a physicist (which is one of the most math intensive disciplines), I don’t consider physics a branch of mathematics, and I’m sure most of my colleagues would whole heartedly agree. Matter of fact, many scientist see mathematics as a separate entity from science itself.

Scientist use mathematics as nothing more than a tool (a very powerful one at that). What distinguishes mathematics separately from physics is while physics employs a tremendous amount of mathematical rigor, it doesn’t use the scope or breathe of mathematics. For instance, in physics we deal with very complex equations called differential equations that contain complex solutions (answers). These answers may have variables or dynamics that a physicist may disregard simply because it doesn’t relate to anything physical or observable. The physicist is only worried about recreating reality through equation(s). Isn’t this what economist attempt to do? Mind you, economist does it awfully just like meteorologist or any other field encompassing chaos. The mathematician on the other hand, is interested in all aspects of the equation & doesn’t care about the constraints of the universe. The mathematician’s world exists in his/her mind that is not bound by the laws of nature. The mathematician considers all aspects of the math while the physicist is only concerned with what he/she needs to describe physical reality.

The most dangerous aspect about mathematics in the social sciences is that there is no underlying elemental structure to social behavior that serves as the basis for mathematical description. In physics and chemistry we have atoms, molecules, macro-aggregates, fields, internal symmetry, external symmetry, and so forth to form the basis for the mathematical construction of equations. This methodology works well because these equations have been formulated independently and the equations themselves have had the ability to predict with fierce accuracy. Or in other words, if there is an alien civilization out there, I’m pretty sure that they would have equivalent logic structures that would equate to the same mathematics and physics. Not so for social sciences.

Another aspect that has made mathematics so vital in physics and chemistry is the equivalency of the equations pertaining to various scopes of physical reality. No where is this more evident than with the Schrodinger Equation from quantum mechanics. Their exist three arenas to the study matter: Thermodynamics (the study of matter at the macro [bulk] scale-what me and you are most familiar with-think of trillions of atoms that make the world around you): Statistical Mechanics (the study of matter between the macro level and quantum level that takes into account large aggregates of matter but not at the level of thermodynamics-millions to hundreds of atoms): Quantum Mechanics (the study of matter at the atomic, molecular, and sub atomic level-a few atoms or less). The Schrodinger Equation, while not resembling the mathematics (formulation) of the equations in both statistical & thermo dynamics has an incredible property! When the Schrodinger Equation is taken too large limits, mathematicaly it transforms into the equations of statistical mechanics, and when those equations are taken to their limits- they translate to the laws of thermo dynamics and classical physics. I seriously doubt that economics has these underlying symmetries that are the central feature of the physical sciences. It’s these underlying symmetries that have made physics and chemistry powerful disciplines in unraveling the behavior of the universe.

Lastly, to develop equations of chaotic systems like the economy or weather systems deals with equations called complex partial differential equations or non linear dynamics. These equations are very difficult to find solutions too because they give a large array of answers for just a single input variable. This is the primary reason why climatologists aren’t able to predict the weather well. Complex systems are complex because they represent systems where population numbers are far too numerous, have too many variables, and too many degrees of freedom.

Any good scientist realizes the limitations of mathematics because it does have limits. Kurt Gödel (a famous mathematician) proved the limitations of mathematics by his famous Incompleteness Theorem, and since has given mathematicians and scientist a sense of humility and humbleness. I just wish some economist would learn Gödel’s theorem.

I must reiterate, just because a field is described by equations doesn’t mean its mathematics. Physics and Chemistry are described by very esoteric & complex equations that encompass many fields of math like complex analysis, real analysis, differential geometry, abstract algebra, group theory, Hilbert space, linear algebra… but in no way shape or form do we consider these disciplines to be a subset of mathematics. Economics doesn’t encompass the mathematical depth of the physical sciences… so how can economics be considered a sub set of mathematics? Mathematics is only a tool in describing phenomena unless it’s purely mathematics itself.

I apologize if any of the above doesn’t make sense. I’m in a hurry.

Excellent post.

I found this part to be particularly enlightening and intriguing, but the whole post was very insightful and offered amazing knowledge.

I thought computation was a branch of mathematics… Boolean logic, Godel’s theorem → Turing machines → Computation. Before it was called computer science, it was often called “applied mathematics”.

I consider (austrian) economics as sort of a branch of philosophy.

Agreed.

Side note: using math in economics didn’t sit well with me while I did my undergrad. That’s why I didn’t minor in economics. I didn’t learn about this Austrian stuff until I was pretty much done my degree in computer science. As soon as I’m done my masters in it, I’ll be doing computer science related stuff for a living, but continue learning (and hopefully start to contribute to) the field of economics as a passion. :slight_smile:

Um…

Its not that mathematics is a subset of logic or logic is a subset of mathematics: mathematics is logic, because the concept of ordinal number is a particular logical form, as is the cardinal number. Mathematics is a different notation, for more complex arguments using cardinal numbers without the hassle of a heterogenous notation used in logic.

Economics is mathematics, in a purely technical language. Just not the type of mathematics that most “professional” economists think it is.

Karl Menger, the younger, once made an article showing how Austrian economists actually use a more mathematically general and powerful tool in their verbal proofs as opposed to the ad hoc limiting assumptions of mainstream economists.

This thread is a definitional mess. I think the OP was getting at this:

IF: We define mathematics as the branch of study that draws necessary conclusions from premises

THEN: Mengerian/Misesian praxeology is a branch of mathematics

(If that is the OP’s point, the OP is definitely correct.)

The issue of whether computational methods are appropriate in economics is entirely separate.

Makes sense.

I would argue that most of physics is axiomatic deductive. Newtonian physics, excepting for gravitation, is. So is Einsteins special theory except for the observation of the constant speed of light. I’m sure there is more, but I don’t know enough about it.

Yep. Very well put AJ.