Thursday, October 3, 2013

The Science of Demand (9) - Unofficial Translation of Steven Cheung's 经济解释 - 科学说需求


There must be a starting point in every debate, and science is no exception. If we have disputes over the starting point, science will be difficult to thrive. Therefore, in scientific development, participants have to comply with a self-evident rule: where a postulate or an axiom is specified, this basis is not arguable. Not that everyone has to whole-heartedly agree with these postulates or axioms. Whether assent or not is not essential, the essence is agreement on not arguing about the starting point. The rules of scientific dialectics are: “First do not oppose to my necessary starting point in theorizing, and let me logically derive from this starting point a set of theory. After testable or refutable implications have been derived, you will then have a basis for opposition. If testable implications are mercilessly refuted by facts, then I cannot but consider my postulates wrong.”

By the way, those postulates or axioms that are not arguable could be quite ridiculous and implausible. For instance, an important postulate in mathematics says: “If one plus one equals a number, that number is called two; and if two plus one equals another number, that number is called three …” Sounds a bit stupid, but without this postulate, we will never know that it is impossible to have another number between one and two. If we have disputes over this basis without any compromise, how could mathematical theories develop?

Let’s cite another example. In geometry, the definition of a straight line is the shortest distance between two points. Sounds like a hard-to-swallow joke, yet it is far less abstract than the postulate of “a point”. Geometry specifies: “A point is not measurable!” If a point is not measurable, how could there be a measurable straight line? Nonetheless, based on these controversial starting points, geometry enabled mankind to build pyramids in ancient times (although these postulates were not at that time clarified), to build Hong Kong’s Bank of China Building today. Our conclusion therefore is: postulates next to ridiculous could lead to amazing knowledge.


The first postulate in economics is: “individual” is the basic unit in economic analysis. That is, when analyzing whatever economic issue, the starting point cannot be from a group of people, an organization, a society or a nation. The analytical unit must be an individual irrespective of macroeconomics, social welfare, or government planning.

No economic theory uses a collective group as the starting point. Regardless of how “macro” the viewpoint is and whether cited at the start of analyzing, if a theory is not based on an “individual” as the starting point, it is no commendable economic theory. That is, it is a must to use an individual as the starting point in analyzing macroeconomics. Certainly, there are economic theories using a group or an entire society as the starting point, but these have divorced from the basis. Occasionally we will hear comments like macro is more important than micro. These would only come from people with no foothold in economics. Macro is made up of the sum of units in terms of individual. The difference between macro and micro is merely whether the combination is big or small. In contemporary economics, the difference between macro and micro, in the eyes of certain scholars, is not according to the degree of combination but rather in accordance with the importance attached to money.

Using “individual” as an analytical unit disregards sex, age, or state of mind. Regardless of whether A is a genius or B is a fool, we consistently treat individual as an analytical unit. As to “individual”, it can be so identified by any observant person. Equally important, postulates cannot be easily altered. The postulate of “individual” is no exception. We cannot use individual as the starting point for certain issues and collective group as the starting point for others. For sure, certain issues concern a group and not an individual, but even when analyzing such collective issue, the starting point remains an individual.

Why is “individual” so important? The answer is all choices are made by an individual. Collective choice is the combination of individual choices. That is, even if an individual loses freedom under a totalitarian regime – without freedom given the circumstances – this individual has nevertheless chosen to give up freedom. In other words, there is neither absolute non-freedom nor absolute freedom in this world. Choice definitely is subject to constraints, yet this choice is made by an individual.

The first postulate in economics is that decision is made by an individual. The so-called decision is choice. It involves a non-trivial philosophy. Economics is a science inferring human behavior to explain phenomena. We profess that all human behavior results from choices. Whether the choice is smart or rational is not essential; of essence is we assume human makes choices. Neither is it essential that all human behavior is actually derived from choices, nor purely by chance without any aim; of essence is we consistently follow this postulate or axiom.

“Human makes choices” is a “convention” in economics. This convention is different from that in other natural sciences. In explaining the phenomenon of an object, physicists will not say the object’s behavior is the result of the object’s choice. In principle, it is not forbidden if physics says objects themselves make choices, though physicists have not done so. Any science has its own established starting point, and this starting point is not arguable. When the “individual makes choices” postulate in economics becomes widely accepted, all economic issues become an issue of choice. There are certainly grounds for the most important theory in economics – the price theory – to be called the choice theory.

In order to apply the choice theory to explain human behavior, it is a must to assume human behavior can be predicted. In a stricter sense, the first axiom in economics is that the behavior of every individual is derived from individual predictable choice. This is an axiom, a postulate in economics. Regardless of right or wrong, this is not arguable.


No comments:

Post a Comment