Friedman
and the defense of “unrealistic assumptions”
Although some contemporary
philosophers have argued that Mill's method a priori is largely defensible
(Bhaskar 1978, Cartwright 1989, and Hausman 1992), by the middle of the
Twentieth Century Mill's views appeared too many economists out of step with
contempo rary philosophy of science. Without studying Mill's text carefully, it
was easy for economists to misunderstand his terminology and to regard his
method a priori as opposed to empiricism. Others took seriously Mill's view
that the basic principles of economics should be empirically established and
found evidence to cast doubt on some of the basic principles, particularly the
view that firms attempt to maximize profits (Hall and Hitch 1938, Lester 1946,
1947). Methodologists who were well- informed about contemporary developments
in philosophy of science, such as Terence Hutchison (1938), denounced
―pure theory‖ in economics as
unscientific.
Philosophically reflective
economists proposed several ways to replace the old- fashioned Millian view
with a more up-to-date methodology that would continue to justify much of
current practice (see particularly Machlup 1955, 1960 and Koopmans 1957). By
far the most influential of these was Milton Friedman's contribution in his
1953 essay, ―The Methodology of Positive Economics.‖ This essay has had an
enormous influence, far more than any other work on methodology.
Friedman begins his essay by
distinguishing in a conventional way between positive and normative economics
and conjecturing that policy disputes are typically really disputes about the
consequences of alternatives and can thus be resolved by progress in positive
economics. Turning to positive economics, Friedman asserts (without argument)
that correct prediction concerning phenomena not yet observed is the ultimate
goal of all positive sciences. He holds a practical view of science and looks
to science for predictions that will guide policy.
Since it is difficult and often
impossible to carry out experiments and since the uncontrolled phenomena
economists observe are difficult to interpret (owing to the same causal
complexity that bothered Mill), it is hard to judge whether a particular theory
is a good basis for predictions or not. Consequently, Friedman argues,
economists have supposed that they could test theories by the realism of their
―assumptions‖ rather than by the accuracy of their predictions. Friedman argues
at length that this is a grave mistake. Theories may be of great predictive
value even though their assumptions are extremely ―unrealistic.‖ The realism of
a theory's assumptions is, he maintains, irrelevant to its predictive value. It
does not matter whether the assumption that firms maximize profits is
realistic. Theories should be appraised exclusively in terms of the accuracy of
their predictions. What matters is whether the theory of the firm makes correct
and significant predictions.
As critics have pointed out (and
almost all commentators have been critical), Friedman refers to several
different things as ―assumptions‖ of a theory and means several different
things by speaking of assumptions as ―unrealistic‖ (Brunner 1969). Since Friedman
aims his criticism to those who investigate empirically whether firms in fact
attempt to maximize profits, he must take
―assumptions‖ to include central
economic generalizations, such as ―Firms attempt to maximize profits,‖ and by
―unrealistic,‖ he must mean, among other things, ―false.‖ In arguing that it is
a mistake to appraise theories in terms of the realism of assumptions, Friedman
is arguing at least that it is a mistake to appraise theories by investigating
whether their central generalizations are true or false.
It would seem that this
interpretation would render Friedman's views inconsistent, because in testing
whether firms attempt to maximize profits, one is checking whether predictions
of theory concerning the behavior of firms are true or false. An ―assumption‖
such as ―firms maximize profits‖ is itself a prediction. But there is a further
wrinkle. Friedman is not concerned with every prediction of economic theories.
In Friedman's view, ―theory is to be judged by its predictive power for the class of phenomena which it is
intended to explain” (1953, p. 8). Economists are interested in only some of the implications of economic theories.
Other predictio ns, such as those concerning the results of surveys of
managers, are irrelevant to policy. What matters is whether economic theories
are successful at predicting the phenomena that economists are interested in.
In other words, Friedman believes that economic theories should be appraised in
terms of their predictions concerning prices and quantities exchanged on
markets. In his view, what matters is
―narrow predictive success‖ (Hausman
2008a), not overall predictive adequacy.
So economists can simply ignore the
disquieting findings of surveys. They can ignore the fact that people do not
always prefer larger bundles of commodities to smaller bundles of commodities.
They need not be troubled that some of their models suppose that all agents
know the prices of all present and future commodities in all markets. All that
matters is whether the predictions concerning market phenomena turn out to be
correct. And since anomalous market outcomes could be due to any number of
uncontrolled causal factors, while experime nts are difficult to carry out, it
turns out that economists need not worry about ever encountering evidence that
would disconfirm fundamental theory. Detailed models may be confirmed or
disconfirmed, but fundamental theory is safe. In this way one can understand
how Friedman's methodology, which appears to justify the eclectic and pragmatic
view that economists should use any model that appears to ―work‖ regardless of
how absurd or unreasonable its assumptions might appear, has been deployed in
service of a rigid theoretical orthodoxy.
Rational
choice theory
Insofar as economics explains and
predicts phenomena as consequences of individual choices, which are they
explained in terms of reasons, it must depict agents as to some extent
rational. Rationality, like reasons, involves evaluation, and just as one can
assess the rationality of individual choices, so one can assess the rationality
of social choices and examine how they are and ought to be related to the
preferences and judgments of individuals. In addition, there are intricate
questions concerning rationality in strategic situations in which outcomes
depend on the choices of multiple individuals. Since rationality is a central
concept in branches of philosophy such as action theory, epistemology, ethics,
and philosophy of mind, studies of rationality frequently cross the boundaries
between economics and philosophy.
Individual
rationality
The barebones theory of rationality
discussed above in Section 1.1 takes an agent's preferences (rankings of
objects of choice) to be rational if they are complete and transitive, and it
takes the agent's choice to be rational if the agent does not prefer any
feasible alternative to what he or she chooses. Such a theory of rationality is
clearly too weak, because it says nothing about belief or what rationality
implies when agents do not know (with certainty) everything relevant to their
choices. But it may also be too strong, since, as Isaac Levi in particular has
argued (1986), there is nothing irrational about having incomplete preferences
in situations involving uncertainty. Sometimes it is rational to suspend
judgment and to defer ranking alternatives that are not well understood. On the
other hand, transitivity is a plausible condition, and the so-called ―money
pump‖ argument demonstrates that if one's preferences are intransitive and one
is willing to make exchanges, then one can be exploited. (Suppose an agent A
prefers X to Y, Y to Z and Z to X, and that A will pay some small amount of
money $P to exchange Y for X, Z for Y, and X for Z. That means that, starting
with Z, A will pay $P for Y, then $P again for X, then $P again for Z and so
on. Agents are not this stupid. They will instead refuse to trade or adjust
their preferences to eliminate the intransitivity (but see Schick 1986).
On the other hand, there is
considerable experimental evidence that people's preferences are not in fact
transitive. Such evidence does not establish that transitivity is not a
requirement of rationality. It may show instead that people are sometimes
irrational. In the case of so-called
―preference reversals,‖ for example,
it seems plausible that people in fact make irrational choices
(Lichtenstein and Slovic 1971,
Tversky and Thaler 1990). Evidence of persistent violations of transitivity is
disquieting, since standards of rationality should not be impossibly high.
.
Collective
rationality and social choice
Although societies are very
different from individuals, they evaluate alternatives and make choices, which
may be rational or irrational. It is not, however, obvious, what principles of
rationality should govern the choices and evaluations of society. Transitivity
is one plausible condition. It seems that a society that chooses X when faced
with the alternatives X or Y, Y when faced with the alternatives Y or Z and Z
when faced with the alternatives X or Z either has had a change of heart or is
choosing irrationally. Yet, purported irrationalities such as these can easily
arise from standard mechanisms that aim to link social choices and individual
preferences. Suppose there are three individuals in the society. Individual One
ranks the alternatives X, Y, Z. Individual Two ranks them Y, Z, X. Individual
Three ranks them Z, X, Y. If decisions are made by pairwise majority voting, X
will be chosen from the pair (X, Y), Y will be chosen from (Y, Z), and Z will
be chosen from (X, Z). Clearly this is unsettling, but is possible cycles in
social choices irrational?
Similar problems affect what one
might call the logical coherence of social judgments (List and Pettit 2002).
Suppose society consists of three individuals who make the following judgments
concerning the truth or falsity of the propositions P and Q and that social
judgment follows the majority.
The judgments of each of the individuals are consistent with
the principles of logic, while social judgments violate them. How important is
it that social judgments be consistent with the principles of logic?
Although social choice theory in
this way bears on questions of social rationality, most work in social choice
theory explores the consequences of principles of rationality coupled with
explicitly ethical constraints. The
seminal contribution is Kenneth Arrow's impossibility theorem (1963, 1967). Arrow assumes that both
individual preferences and social choices are complete and transitive and (as
completeness implies) that the method of making social choices issues in some
choice for any possible profile of individual preferences. In addition, he
imposes a weak unanimity condition: if everybody prefers X to Y, then Y must
not be chosen. Third, he requires that there be no dictator whose preferences
determine social choices irrespective of the preferences of anybody else.
Lastly, he imposes the condition that the social choice between X and Y should
depend on how individuals rank X and Y and on nothing else. Arrow then proved
the surprising result that no method of relating social choices and individual
preferences can satisfy all these conditions!
In the sixty years since Arrow
wrote, there has been a plethora of work in social choice theory, a good deal
of which is arguably of great importance to ethics. For example, John Harsanyi
proved that if individual preferences and social evaluations both satisfy the
axioms of expected utility theory (with shared or objective probabilities) and
a stronger unanimity condition is imposed, then social evaluations are
determined by a weighted sum of individual utilities (1955, 1977a). Matthew
Adler (2012) has recently extended an approach like Harsanyi's to demonstrate
that a form of weighted utilitarianism, which prioritizes the interests of
those who are worse off, uniquely satisfies a longer list of rational and
ethical constraints. When there are instead disagreements in probability
assignments, there is an impossibility result: the unanimity condition implies
that social evaluations will not satisfy the axioms of expected utility theory
(Hammond 1983, Seidenfeld, et al. 1989, Mongin 1995). For further discussion of
social choice theory and the relevance of utility theory to social evaluation,
see Sen (1970) and for recent reappraisals Fleurbaey (2007) and Adler (2012).
Game
theory
When outcomes depend on what several
agents do, one agent's best choice may depend o n what other agents choose. Although
the principles of rationality governing individual choice still apply, arguably
there are further principles of rationality governing e xpectations of the
actions of others (and of their expectations concerning your actions and
expectations, and so forth). Game theory occupies an increasingly important
role within economics itself, and it is also relevant both to inquiries
concerning rationality and inquiries concerning ethics. For further discussion
see the entries on Game Theory, Game Theory and Ethics, and Evolutionary Game
Theory.
Economics
and ethics
As discussed above in Section 2.1 most economists distinguish between positive and normative
economics, and most would argue that economics is mainly relevant to policy
because of the (positive) information it provides concerning the consequences
of policy. Yet the same economists also offer their advice concerning how to
fix the economy. In addition, there is a whole field of normative economics.
Economic outcomes, institutions, and
processes may be better or worse in several different ways. Some outcomes may
make people better off. Other outcomes may be less unequal. Others may restrict
individual freedom more severely. Economists typically evaluate outcomes
exclusively in terms of welfare. This does not imply that they believe that
only welfare is of moral importance. They focus on welfare, because they
believe that economics provides a particularly apt set of tools to address
questions of welfare and because they believe or hope that questions about
welfare can be separated from questions about equality, freedom, or justice. As
sketched below, economists have had some things to say about other dimensions
of moral appraisal, but welfare takes center stage. Indeed normative economics
is often called ―welfare economics.‖
Welfare
One central question of moral
philosophy has been to determine what things are intrinsically good for human
beings. This is a central question, because all plausible moral views assign an
important place to individual welfare or well-being.
This is obviously true of
utilitarianism (which hold that what is right maximizes total or average
welfare), but even non-utilitarian views must be concerned with welfare, if
they recognize the virtue of benevolence, or if they are concerned with the
interests of individuals or with avoiding harm to individuals.
There are many ways to think about
well-being, and the prevailing view among economists themselves has shifted
from hedonism (which takes the good to be a mental state such as pleasure or
happiness) to the view that welfare can be measured by the satisfaction of
preferences.
Efficiency
Because the identification of
welfare with preference satisfaction makes it questionable whether one can make
interpersonal welfare comparisons, few economists defend a utilitarian view of
policy as maximizing total or average welfare. (Harsanyi is one exception, for
another see Ng 1983). Economists have instead explored the possibility of
making welfare evaluations of economic processes, institutions, outcomes, and
policies without making interpersonal comparisons. Consider two economic
outcomes S and R, and suppose that some people prefer S to R and that nobody
prefers R to S. In that case S is ―Pareto superior‖ to R, or S is a ―Pareto
improvement‖ over R. Without making any interpersonal comparisons, one can
conclude that people's preferences are better satisfied in S than in R. If
there is no state of affairs that is Pareto superior to S, then economists say
that S is ―Pareto optimal‖ or ―Pareto efficient.‖ Efficiency here is efficiency
with respect to satisfying preferences rather than minimizing the number of
inputs needed to produce a unit of output or some other technical notion
(Legrand 1991). If a state of affairs is not Pareto efficient, then society is
missing an opportunity costlessly to satisfy some people's preferences better.
A Pareto efficient state of affairs avoids this failure, but it has no other
obvious virtues. For example, suppose nobody is satiated and people care only
about how much food they get. Consider two distributions of food. In the first,
millions are starving but no food is wasted. In the second, nobody is starving,
but some food is wasted. The first is Pareto e fficient, while the second is
not.
Other
directions in normative economics
Although welfare economics and
concerns about efficiency dominate normative economics, they do not exhaust the
subject, and in collaboration with philosophers, economists have made various
important contributions to contemporary work in ethics and normative social and
political philosophy. Section 5.2 and Section 5.3 gave some hint of the
contributions of social choice theory and game theory. In addition economists
and philosophers have been working on the problem of providing a formal
characterization of freedom so as to bring tools of economic analysis to bear
(Pattanaik and Xu 1990, Sen 1988, 1990, 1991, Carter 1999). Others have
developed formal characterizations of equality of resources, opportunity, and
outcomes and have analyzed the conditions under which it is possible to
separate individual and social responsibility for inequalities (Pazner and
Schmeidler 1974, Varian 1974, 1975, Roemer 1986b, 1987, Fleurbaey 1995, 2008).
John Roemer has put contemporary economic modeling to work to offer precise
characterizations of exploitation (1982). Amartya Sen and Martha Nussbaum have
not only developed novel interpretations of the proper concerns of normative
economics in terms of capabilities (Sen 1992, Nussbaum and Sen 1993, Nussbaum
2000), which Sen has linked to characterizations of egalitarianism and to
operational measures of deprivation (1999). There are many lively interactions
between normative economics and moral philosophy. See also the entries on
Libertarianism, Paternalism, Egalitarianism, and Economic Justice.
Conclusions
The frontiers between economics and
philosophy concerned with methodology, rationality, ethics and normative social
and political philosophy are buzzing with activity. This activity is diverse
and concerned with very different questions. Although many of these are
related, philosophy of economics is not a single unified enterprise. It is a
collection of separate inquiries linked to one another by connections among the
questions and by the dominating influence of mainstream economic models and
techniques.
Main Features of a Planned Economy
If we have a look at the planned economies, say, Russian, Chinese or even
Indian economy, we shall discover some characteristics. The formulation of the
plan and its implementation call for a certain type of economic and
administrative organization and a certain type of endeavor and set- up. It is
only natural, therefore, that the planned economies reveal some common
features.
Existence of a Central Planning
Authority
Related Topics
Privacy Policy, Terms and Conditions, DMCA Policy and Compliant
Copyright © 2018-2023 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.