Post on 30-Dec-2015
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Research Methods
Lecture 2: Positivism, its variants and its impact on Economics
Why study Positivism?
• Hughes & Sharrock (1997: 24): positivism was ≈ orthodoxy in social science
• No longer believed? (Williams, 1976)
• Yet economics still heavily influenced
• Authors defined in terms of positivism
• Positivist tools (e.g. survey) still dominate
• Must try to give it a fair hearing!
Roots of positivism• Renaissance/Enlightenment thought of
16th/17th Centuries• Philosophy divided into empiricism/
rationalism: foundation of knowledge experience/reason; Bacon/Descartes
• Saint-Simon: liberate people from dominant ideas; French Revolution
• Get past illusions to “social facts” (Durkheim)
Comte’s positivism• Influenced by Hume’s attacks on
metaphysics
• Two bona-fide forms of knowledge: empirical and logical, but empirical emphasised
• Precision, clarity and certainty
• View world as machine (reflects Descartes)
• World comprises deterministic laws, regularities; waiting to be discovered by the scientist
Positivism: basics
• Laws: whenever A, then B (plus CP)
• Causality: constant conjunctions of events (Hume)
• Single cause leads to single effect (Durkheim)
• Mill’s tendency statements, Hume’s caution both too weak for modern positivists
Scientistic naturalism
• Social science should imitate natural sciences (although why? Never stated!)
• Aim for “unity of method”
• Differences acknowledged between subject matters
• Science proceeds via observation, modelling, to get to laws
Observation• “Brute facts” (not affected by any judgement):
mimic natural sciences (e.g. atom, velocity)• Observation is preconception free (Durkheim) and
Value-free (positive analysis)• Correspondence theory of truth• Variables; measuring properties present in entities• Quantification: counting frequency of some
property present in some entity• Operationalism: object defined in terms of the
means of measuring/checking it (Hausman: 14)
Theory development
• Individualism; reductionism
• Modelling
• Testing predictions of models
• Verification
• H-D model tries to solve problem of induction
Logical positivism
• Carnap, Mach (Vienna Circle), Ayer, Russell: trying to make positivism more logical
• Meaningful (True) statements must be verifiable
• But now analytic statements can be true by virtue of the logical rules by which they are deduced
• Yet LP questioned ‘ideal types’
Popper’s intervention
• Karl Popper: capturing spirit of positivism in many ways but opposite in others
• Sceptic: verification impossible
• No theory proven; yet to be falsified
• “Scientific” theories are testable
• Theories set up bold conjectures to be tested
• Test theories by their predictions
Popper’s intervention
• Falsification from a single counterexample
• Learning by trial and error
• Idealised view of science
• Kuhn, Lakatos: Popper underestimated tenacity with which “failed” theories are retained
• Kuhn: sciences proceed irrationally; normal vs. revolutionary science
Friedman (1953)
• Highly influential essay
• Can be interpreted as combining elements of positivism with Popper
• “positive economics”
• Purpose of theory = prediction
• Good theories predict well
• Simplicity and precision also good
Friedman
• Assumptions of theories not important• Assumptions are always simplifications -
cannot be “realistic” - cannot assess theory via “realisticness”
• Assumptions are shorthand for conditions, etc. under which theory works
• Model works “as if” assumptions are correct: e.g. mobile leaves; profit maximisation
Conclusions
• Positivism has had several highly significant effects on economics:
• Mimic natural sciences• “Value-free” analysis• Causal laws: “if X then Y” type• Quantification • Tools used• Emphasis on deductive logic
Conclusions
• H-D model• Friedman also very influential• Assertions about “positive” economics, the role of
assumptions, prediction and falsification (echoing Popper) adopted strongly (at least “officially”)
• Both subject to considerable criticism• Next two lectures will engage criticisms of
positivism and its variants