The Role of Economic Theory and Controversy

The Role of Economic Theory and Controversy
An understanding by government policy makers of the factors which determine
the long-run growth of an economy and the short-run fluctuations that constitute
the business cycle is essential in order to design and implement economic
policies which have the potential vastly to improve economic welfare. The
primary aim of macroeconomic research is to develop as comprehensive an
understanding as possible of the way the economy functions and how it is
likely to react to specific policies and the wide variety of demand and supply
shocks which can cause instability. Macroeconomic theory, consisting of a set
of views about the way the economy operates, organized within a logical
framework (or theory), forms the basis upon which economic policy is designed
and implemented. Theories, by definition, are simplifications of reality.
This must be so given the complexity of the real world. The intellectual problem
for economists is how to capture, in the form of specific models, the
complicated interactive behaviour of millions of individuals engaged in economic
activity. Huntington (1996) has succinctly outlined the general case for
explicit modelling as an essential aid to thought:
Simplified paradigms or maps are indispensable for human thought. On the one
hand, we may explicitly formulate theories or models and consciously use them to
guide behaviour. Alternatively, we may deny the need for such guides and assume
that we will act only in terms of specific ‘objective’ facts, dealing with each case
‘on its own merits’. If we assume this, however, we delude ourselves. For in the
back of our minds are hidden assumptions, biases, and prejudices that determine
how we perceive reality, what facts we look at, and how we judge their importance
and merits.
Accordingly, explicit or implicit models are necessary to make sense of a very
complex world. By definition economic theories and specific models act as the
laboratories we otherwise lack in the social sciences. They help economists
decide what are the important factors that need to be analysed when they run
thought experiments about the causes and consequences of various economic
phenomena. A successful theory will enable economists to make better predictions
about the consequences of alternative courses of action thereby indicating
the policy regime most likely to achieve society’s chosen objectives.
The design of coherent economic policies aimed at achieving an acceptable
rate of economic growth and reduced aggregate instability depends then
on the availability of internally consistent theoretical models of the economy
which can explain satisfactorily the behaviour of the main macro variables
and are not rejected by the available empirical evidence. Such models provide
an organizing framework for reviewing the development and improvement
of institutions and policies capable of generating reasonable macroeconomic
stability and growth. However, throughout the twentieth century, economists
have often differed, sometimes substantially, over what is to be regarded as
the ‘correct’ model of the economy. As a result, prolonged disagreements and
controversies have frequently characterized the history of macroeconomic
thought (Woodford, 2000).
The knowledge that macroeconomists have today about the way that economies
function is the result of a prolonged research effort often involving
Understanding modern macroeconomics 5
intense controversy and an ever-increasing data bank of experience. As
Blanchard (1997a) points out:
Macroeconomics is not an exact science but an applied one where ideas, theories,
and models are constantly evaluated against the facts, and often modified or
rejected … Macroeconomics is thus the result of a sustained process of construction,
of an interaction between ideas and events. What macroeconomists believe
today is the result of an evolutionary process in which they have eliminated those
ideas that failed and kept those that appear to explain reality well.
Taking a long-term perspective, our current understanding of macroeconomics,
at the beginning of the twenty-first century, is nothing more than yet
another chapter in the history of economic thought. However, it is important
to recognize from the outset that the evolution of economists’ thinking on
macroeconomics has been far from smooth. So much so that many economists
are not averse to making frequent use of terminology such as ‘revolution’
and ‘counter-revolution’ when discussing the history of macroeconomics.
The dramatic decline of the Keynesian conventional wisdom in the early
1970s resulted from both the empirical failings of ‘old Keynesianism’ and the
increasing success of critiques (‘counter-revolutions’) mounted by monetarist
and new classical economists (Johnson, 1971; Tobin, 1981, 1996; Blaug,
1997; Snowdon and Vane, 1996, 1997a, 1997b).
In our view, any adequate account of the current state of macroeconomics
needs to explore the rise and fall of the old ideas and the state of the new
within a comparative and historical context (see Britton, 2002). This book
examines, compares and evaluates the evolution of the major rival stories
comprising contemporary macroeconomic thought. We would maintain that
the coexistence of alternative explanations and views is a sign of strength
rather than weakness, since it permits mutual gains from intellectual trade
and thereby improved understanding. It was John Stuart Mill who recognized,
almost one hundred and fifty years ago, that all parties gain from the
comparative interplay of ideas. Alternative ideas not only help prevent
complacency, where ‘teachers and learners go to sleep at their post as soon
as there is no enemy in the field’ (Mill, 1982, p. 105), but they also provide
a vehicle for improved understanding whereby the effort to comprehend
alternative views forces economists to re-evaluate their own views. Controversy
and dialogue have been, and will continue to be, a major engine for
the accumulation of new knowledge and progress in macroeconomics. We
would therefore endorse Mill’s plea for continued dialogue (in this case
within macroeconomics) between the alternative frameworks and suggest
that all economists have something to learn from each other. The macroeconomic
problems that economists address and endeavour to solve are
often shared.
That there is a wide variety of schools of thought in economics in general,
and macroeconomics in particular, should not surprise us given the intrinsic
difficulty and importance of the issues under investigation. While there are
‘strong incentives in academia to differentiate products’ (Blanchard and Fischer,
1989), there is no doubt that much of the controversy in macroeconomics
runs deep. Of course, it is true that economists disagree on many issues, but
they seem to do so more frequently, vociferously, and at greater length, in
macroeconomics. In his discussion of why there is much controversy in
macroeconomics Mayer (1994) identifies seven sources, namely, limited knowledge
about how the economy works, the ever-widening range of issues that
economists investigate, the need to take into account wider influences, such
as political factors, and differences in the ‘metaphysical cores, value judgements,
social empathies and methodologies’ of various economists. Knut
Wicksell’s (1958, pp. 51–2) contention that within economics ‘the state of
war seems to persist and remain permanent’ seems most appropriate for
contemporary macroeconomics. To a large extent this reflects the importance
of the issues which macroeconomists deal with, but it also supports the
findings of previous surveys of economists which revealed a tendency for
consensus to be stronger on microeconomic compared to macroeconomic
propositions (see, for example, Alston et al., 1992).
It is certainly true that in specific periods during the twentieth century the
contemporary state of macroeconomic theory had the appearance of a battlefield,
with regiments of economists grouped under different banners. However,
it is our view that economists should always resist the temptation to embrace,
in an unquestioning way, a one-sided or restrictive consensus ‘because the
right answers are unlikely to come from any pure economic dogma’ (Deane,
1983). In addition, the very nature of scientific research dictates that disagreements
and debate are most vocal at the frontier, as they should be, and, as
Robert E. Lucas Jr argues (see interview at the end of Chapter 5), the responsibility
of professional economists is ‘to create new knowledge by pushing
research into new, and hence necessarily controversial, territory. Consensus
can be reached on specific issues, but consensus for a research area as a
whole is equivalent to stagnation, irrelevance and death.’ Furthermore, as
Milton Friedman observes (see interview at the end of Chapter 4), ‘science in
general advances primarily by unsuccessful experiments that clear the ground’.
Macroeconomics has witnessed considerable progress since its birth in the
1930s. More specifically, any Rip Van Winkle economist who had fallen
asleep in 1965, when the ‘old Keynesian’ paradigm was at its peak, would
surely be impressed on waking up at the beginning of the twenty-first century
and surveying the enormous changes that have taken place in the macroeconomics
literature.