Basic Microeconomics by Professor R. Larry Reynolds, PhD - HTML preview

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and regression can be used to relate different aspects (variables) in the data

set. The strength of the relationships that are recognized in the data set can

the tested using t-scores, F-ratios, Chi Square and other methods. At the end

of the day, none of these methods can prove causation: they can only show

correlation. The concept of causation depends on a theory (or hypothesis)

about the relationship between the variables. Statistical methods allow a test

of the hypothesis or theory. The hypothesis cannot be proven it can only be

disproven and the hypothesis rejected. Statistics can be used as evidence to

support or reject a perception of causation.

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3.3 Foundations of “Science”

CHANCE

If the world of events were truly a machine subject to the law of causes,

events would be deterministic. Bronowski argues that the recognition of the

law of chance is central to the method of science. It adds “statistical law” to

the concept of “causal law.” (Bronowski,. p 82) Causal law states that event B

is caused by event A and therefore, event B will follow event A 100 time out of

100 occurrences of event A. Statistical law is based on the notion that event B

will “probably” follow event A. The process is described as one where:

“We look for a trend or systematic difference. But the line of this trend

will itself be blurred by the unsteady hand of chance or random

fluctuation. We cannot get rid of this random scrawl. But we can from it

determine a measure of random variation, and use that to draw round

the trend an area of uncertainty. If the area is small enough by

standards which are agreed between us, then the trend is established,

and we know the limits within which it is likely to lie. (Bronowski, p

92)

The concept of probability provides the method by which observations of an

extraordinarily complex world can be interpreted. It gives us information and

knowledge that may not be “true” but is useful.

In a complex world, there may be many reasons for a lack of certainty in

causes. There may be other hidden or unrecognized forces that influence the

relationship between event A and event B. If event A results in event B 90%

of the time we may believe that A “causes” B. If the occurrence of A results in

event B 30% of the time, other “causes” of B may be more important.

Probability is a key idea in the understanding of causes. Statistics provides the

means to state that with 95% confidence (or some other percentage) event A

is correlated with event B.

USEFULNESS AND “TRUTH”

Knowledge held at any time may be “true” or “not true.” Knowledge that is

true may or may not be useful. Knowledge may be useful whether it is “true”

48

3.3 Foundations of “Science”

or not. Before the Copernican Revolution, a common belief was that the Earth

was a stationary center of the universe. This was the Ptolemaic system

attributed to Claudius Ptolemy [127-151 AD], a Greek mathematician and

astronomer who lived in Egypt. In this system, the sun, stars, planets and

moon circled the Earth in repeated patterns. Complex models were

constructed to explain and predict the paths of the objects. These models

worked with reasonable accuracy and were useful to plan for seasons, planting

of crops, and to prepare for floods. The models were useful, but “wrong.” New

information obtained through observation and measurement showed there

were simpler explanations for the paths of the celestial bodies. The Copernican

or heliocentric view gained dominance. Galileo [1564-1642] verified the

Copernican system with a new technology (the telescope). Johann Kepler

[1571-1630] improved on Galileo’s findings and calculated equations to

explain the elliptical orbits of the planets about the sun. As we accept “new

knowledge” about the cosmos and subatomic matter, we replace old truths

with new truths.

49

3.4 Explanation, Prediction and Storytelling

3.4 EXPLANATION, PREDICTION AND STORYTELLING

Explanation and prediction are two of major objectives of science. These

two goals are not symmetrical: it is possible to explain an event or

phenomenon without being able to predict the probability of its occurrence: at

the same time, it is possible to predict an event without being able to explain

its nature or causes. Mark Blaug identifies two problems that arise from the

“Symmetry Thesis.” First is the problem: “the history of science contains a

number of theories which appear to explain natural phenomena, without

however predicting them even in a statistical sense.” (Blaug, 1986, p 274)

Darwin’s theory of evolution is cited as an example.

Second is the problem: “…science, and particularly social science, abound

in rules-of-thumb that yield highly accurate predictions about both natural and

social events despite the fact that we may have absolutely no idea why these

rules-of-thumb work as well as they do. (Ibid.)

Whether explaining or predicting, science places value on precision and

rigor of the process. However, one should avoid using the same criteria to

evaluate scientific models with different objectives. It is also necessary to

avoid attempts at precision and rigor that are not possible. Thomas Mayer

cautions economists (the warning applies to all disciplines):

“...we should draw a much sharper distinction that is usually done

between two types of economic theory. One, formalist theory is abstract

theory that is concerned with high-level generalization and looks

towards axiomization. The other, empirical science theory focuses on

explaining past observations and predicting future ones. While both are

perfectly legitimate, applying the criteria appropriate to one to evaluate

the other generates confusion and misunderstanding. (Mayer’s

book)...is a plea for a more modest economics that recognizes the

inherent difficulty of making precise and indubitable statements about

the actual world, accepts that there is a trade-off between rigor and

relevance. I certainly agree that one should be as rigorous as one can

be: I just oppose trying to be as rigorous as one can not be.” (Mayer, p

50

3.4 Explanation, Prediction and Storytelling

7)

An emphasis on rigor and precision may result in attempts to develop

theories or models that are esoteric and of little interest to anyone other than

the scientist-author.

In addition to explanation and prediction, science and the stories of science

also create, shape and transmit individual and social values. Often this is an

unintended effect rather than a conscious objective. The study of the evolution

of methods in a discipline, such as economics, will hopefully create a greater

awareness of this role and a greater understanding of one of the important

effects.

3.5 LOGIC

Several processes can be used in the discovery, creation and justification

of knowledge. Instinct, intuition, abduction, deduction, induction and authority

are examples of sources of knowledge. Appeals to authority as a justification

for acceptance of knowledge is common but is not a reliable source. Instinct,

intuition and introspection were once of great importance, but are not often

seen as credible as “science” when seeking justifications for “knowledge” in

Western, industrial societies. Research in the cognitive sciences and behavioral

economics has recently been investigating intuition as a means of decision-

making. Daniel Kahneman (a psychologist) received the Nobel in economics

for work in cognitive processes and intuition in economic decisions. However,

most discussions of methods in science place primary emphasis on inductive

and deductive processes.

51

3.5.1 Deductive Reasoning

3.5.1 DEDUCTIVE REASONING

Aristotle (384-322BCE) is usually credited with formalizing syllogistic or

deductive reasoning. Deductive reasoning is a process that starts with a set of

premises (or a priori truths) or general principles and through rules of logic,

“deduces” a conclusion about a specific case. There are usually two premises:

a major premise and a minor premise. If the general principle or major

premise were that all the water in the lake was safe to drink, then deductive

reasoning would conclude that a specific glass of water from the lake (the

minor premise is the water is from the lake) is safe to drink. The internal logic

could be correct but if either of the premises were false, correct deductive

logic would not yield true conclusions.

3.5.2 INDUCTIVE REASONING

Francis Bacon (1561-1626) is credited with formalizing inductive

reasoning. J.E. Creighton argues that Bacon’s N

ovum O

rganum was to replace

Aristotle as the preeminent guide to the process of acquiring knowledge.

“Bacon did for inductive logic what Aristotle did for the theory of the

syllogism. It is of course, incorrect to say, as has sometimes been said,

that Bacon invented the inductive method of reasoning. … What Bacon

endeavored to do was to analyze the inductive procedure, and to show

what conditions must be fulfilled in order that truth may be reached in

this way.” (Bacon, pps vii-viii)

Inductive reasoning is the process of inferring information from empirical

observations. If several glasses of water were taken from a lake and each

glass of water was shown to be safe to drink, it might be “inferred” that the

water in the lake is safe to drink. Because all the water in the lake was not

(and possibly could not) be tested there is some probability that all the water

in the lake is not safe to drink. Empiricism is rooted in the inductive process

52

3.5.2 Inductive Reasoning

and is based on empirical observations. Statistical inference is an application

of the inductive method.

While inductive methods are useful, there are pitfalls to avoid. Observations

might be incomplete or the interpretation of the observation(s) could be

incorrect. The selection of which phenomena to observe and the sequencing of

the “facts” can alter the conclusions reached. The application of inference and

inductive methods requires judgment and caution in the interpretation of data.

3.5.3 ABDUCTIVE REASONING

Abduction is a creative process from which hypotheses arise. Abduction is

similar to induction. The differences are that abduction is less formal process

that consists of a combination of intuition, experience, observation, deductive

reasoning and generates hypotheses which could be wrong. Abduction is the

insight that occurs with less conscious formal reasoning than either induction

or deduction.

It is the purpose of inductive and deductive reasoning to test the

hypotheses that emerge from the process of abduction.

3.6 EPISTEMOLOGY AND ECONOMIC METHODOLOGY

Epistemology is the study of the nature and limits of knowing. Economists

are confronted with an ocean of facts and data that are reputed to support a

plethora of theories and laws that purport to be the “truth” about economic

behavior. Any discipline, whether it is economics, physics, biology or …,

advances because someone questions the received wisdom: both extensions

of ideas and new ideas that are created as reactions against result from

questions about the received wisdom. If a scientist, economist or practitioner

of any discipline has the “truth,” their only task is to make sure others accept

53

3.6 Epistemology and Economic Methodology

that “truth.” A bit of humility about what one thinks they know is not a bad

thing. A quick survey of some of the basic ideas in epistemology provides an

enlightened humility.

3.6.1 A TAXONOMY OF KNOWLEDGE

Joel Mokyr classifies knowledge as propositional and prescriptive

knowledge. Mokyr, an economic historian, relates the problem of human

knowledge to economic growth and the economic problem. Propositional

knowledge is “.. knowledge (that is to say beliefs) about natural phenomena

and regularities.” (Mokyr, p 4) Prescriptive knowledge is instructional or

knowledge about techniques about how to do something. (ibid)

3.6.1.1 PROPOSITIONAL KNOWLEDGE

In Mokyr’s taxonomy, propositional knowledge (Ω) can take two forms.

He describes these as (1) “the observation, classification, measurement, and

cataloging of natural phenomena.” And (2) “the establishment of regularities,

principles and ‘natural laws’ that govern these phenomena and allow us to

make sense of them. ” Mokyr’s characterization of propositional knowledge is:

“Science, as John Ziman has emphasized, is the quintessential form of

public knowledge, but propositional knowledge is much more: the

practical informal knowledge about nature such as the properties of

materials, heat, motion, plants and animals: and intuitive grasp of basic

mechanics (including the six ‘basic machines of classical antiquity: the

lever, pulley, screw, balance, wedge and wheel): regularities of the

ocean currents and the weather: and folk wisdom in the ‘apple-a-day-

keeps-the-doctor-away’ tradition. Geography is very much a part of it:

knowing were things are is logically prior to the instructions of how to

go from here to there.” (Mokyr, p 5)

He argues that for the economic historian what matters is the collective

knowledge of what society, as a whole, knows (the union of all statements of

such knowledge). Confidence and consensus about knowledge as well as

54

3.6.1 A Taxonomy of Knowledge

access to and transmittal of that knowledge is of great importance to how

propositional knowledge is used. Mokyr characterizes the development of new

propositional knowledge as “discovery, the unearthing of a fact of natural law

that existed all along but was unknown to anyone in society. ” (Mokyr,, p 10)

3.6.1.2 PRESCRIPTIVE KNOWLEDGE

Prescriptive knowledge (λ) is the knowledge about how to do something:

it is technique or instructional knowledge. This prescriptive knowledge is

defined as “sets of executable instructions or recipes for how to manipulate

nature. ” (Mokyr,, p 10) The addition to this prescriptive knowledge is called an

invention.” Prescriptive knowledge is not right or wrong it is successful or

unsuccessful. Mokyr argues that the industrial revolution and the associated

economic growth began when prescriptive knowledge came to be based on

proportional knowledge. Individuals can learn to do things without knowing

why they work. Once you know why techniques (prescriptive knowledge)

work, (propositional knowledge), it is easier to invent improvements to old

techniques and develop of new ones.

3.6.1.3 AN EXAMPLE

Knowledge about baking includes an understanding of the effects of

altitude, leavening, moisture, temperature, gluten and a host of other

phenomena on cakes. This knowledge is propositional knowledge. A cake can

be baked by someone in San Francisco with a recipe (prescriptive knowledge)

and no knowledge about the effects of altitude on cakes. The recipe will work

as long as person doesn’t try to bake a cake in Santa Fe, NM (elevation 7200

feet). To modify the recipe so it will work at the new elevation requires

propositional knowledge. The development of new recipes (λ) requires some

proportional knowledge (Ω).

55

3.6.2 Brief Survey of Epistemology

3.6.2 BRIEF SURVEY OF EPISTEMOLOGY

Karl Popper [1902-1994] is the primary architect of falsification as a

method of science. In his T

he L ogic of Scientific Discovery , 1934, he outlines

the basic approach taken in what is called the scientific method. He proposes

that scientific knowledge grows through a process of making hypotheses abut

the nature of problems and the falsification or testing of those hypotheses.

Popper argues that it is the duty of every scientist to try to disprove or reject

his or her hypotheses. If a hypothesis cannot be rejected by empirical

evidence, it may be retained as “probably true.” All knowledge then is

probabilistic: it has not yet been falsified. The process is subject to what

statisticians call Type I and II (or alpha and beta) errors. Type II errors occur

when a false hypothesis is accepted as “true.” When a “true” hypothesis is

rejected as false a Type I error has occurred.

Thomas Kuhn [ The Structure of Scientific Revolutions, 2cd ed, 1962,1970]

offers another explanation for the evolution and change of scientific thought in

the “hard sciences.” His explanation is often applied to economics and social

sciences. Kuhn used the concept of “paradigms” and paradigm shifts to explain

the process. The term, paradigm, is often used and abused in discussions.

Kuhn’s approach is essentially a “truth by consensus” which is contained in

the paradigm. This paradigm (and its associated “truth by consensus”) is

practiced until there are “anomalies” or problems that the existing paradigm

cannot explain. Then an alternative paradigm with greater explanatory powers

replaces it. He argues that a science operates within a paradigm. This

paradigm is characterized by,

• the “community structure of science’

• or the “disciplinary matrix” which consists of symbolic generalizations

(deployed without question),

• shared commitments to a set of beliefs and a set of values.

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3.6.2 Brief Survey of Epistemology

The members of the science use this paradigm to resolve anomalies. When

an anomaly of major significance or a large number of anomalies cannot be

explained, the paradigm must be questioned and a new paradigm for that

science developed. In this manner “science progresses.”

Imre Lakatos’ method is expressed in his book, Proofs and Refutations,

[Cambridge University Press: Cambridge, 1976]. Lakatos’ approach, while in

the tradition of one of his teachers, Karl Popper, is critical of both Popper and

Kuhn. He advocated a more sophisticated form of falsification of “groups of

theories” and combined it with “scientific research programmes (SRP’s)” which

were more specific than paradigms. Lakatos’ SRP consists of two elements,

the “hard core, protective belt” and the “positive heuristic.” (Pheby, John,

Methodology and Economics: a Critical Introduction, M.E.Sharpe, 1988,, p 56)

The hard core is constructed of “basic axioms and hypotheses” that are

accepted without question and is used as a defense mechanism. The positive

heuristic is the body of theories and problems that drive the research

programmes. (Pheby, p 56)

Kuhn’s approach can be contrasted with that of Karl Popper and Imre

Lakatos. Popper saw the advancement of knowledge as the result of the

falsification of testable hypotheses. Those hypotheses that were not disproved

were accepted as “probably true.” Lakatos took the middle ground. Rather

than falsifying a hypothesis or the whole paradigm, he felt that the process

was based on “scientific research programs.” A school of economic thought

may represent a paradigm (in a Kuhnian sense) or a scientific research

program (in a Lakatian sense).

A more extreme view is expressed in Paul Feyerabend’s book, Against

Method (Verso: London, 1988, originally published by New Left Books, 1975).

He advocates an approach to science that has been called “theoretical

57

3.6.2 Brief Survey of Epistemology

anarchism.” Feyerabend argues that the “success of science cannot be used as

an argument for treating yet unsolved problems in a standardized way” and

scientific achievements can “be judged only after the event.” (Feyerabend, p

2) Feyerabend’s approach to the methodology of science is radically different

because of his objectives. He claims his purpose is “humanitarian not

intellectual” in that he wants “to support people not advance knowledge.” He

is “against ideologies that use the name of science for cultural murder.”

(Feyerabend, p 4]) While he does not disavow the title of “theoretical

anarchist,” he does provide insights into the evolution of science and

knowledge. Feyerabend summarizes some of his insights:

“Neither science nor rationality are universal measures of excellence.

They are particular traditions, unaware of their historical grounding.”

(Feyerabend, p 231)

“Yet it is possible to evaluate standards of rationality and to improve

them. The principles of improvement are neither above tradition nor

beyond change and it is impossible to nail them down.” (Feyerabend,

p 248)

“Science is a tradition among many and a provider of truth only for

those who have made the appropriate cultural choice.” (Feyerabend, p

256)

“The entities postulated by science are not found, and they do not

constitute an ‘objective’ stage for all cultures and all of history. They are

shaped by special groups, cultures, civilizations: and they are shaped

from a material which depending on its treatment, provides us with