Definitions[edit]
The scientific or positive aspects of economics were emphasized by many 20th century economists in order to show that economic theories could answer questions with the same scientific methodology as the physical sciences.[6]
John Neville Keynes's The Scope and Method of Political Economy defined positive economics as the science of "what is" as compared to normative economics, the study of "what ought to be".[2] Keynes was not the first person to make these distinction between positive and normative economics but his definitions have become the standard in economics teaching.[7]
Lionel Robbins's 1932 book An Essay on the Nature and Significance of Economic Science stated that economics should take as its subject matter attempts by individuals to achieve ends with limited resources. Given that any end was "dependent on scarce means", it should not take a point of view on which ends should or should not be pursued.[8] It is believed that Robbins was instrumental in promoting the fact-value distinction in economics and insisting that ethical or value judgments should not be a part of the discipline, however Robbins' views on this subject were not entirely clear.[7]
Paul Samuelson's Foundations of Economic Analysis (1947) lays out the standard of operationally meaningful theorems through positive economics. Positive economics is commonly deemed necessary for the ranking of economic policies or outcomes as to acceptability.[9]
Milton Friedman, in an influential 1953 essay, elaborated on the distinctions between positive and normative economics. He defined the aim of positive economics as developing theories that give “valid and meaningful” predictions which are precise, testable and in accordance with the available empirical evidence.[6] To do this, economists must create a model that simplifies reality.
Friedman also emphasized that positive and normative economics could never be entirely separated because of their relationship with economic policy. Disagreements about economic policy are primarily due to an inability to agree about the likely consequences of a piece of legislation. As economics developed, Friedman believed that it would become increasingly possible to derive undisputed results about positive economic statements and that this would help to make clear judgments about the best ways to achieve normative goals such as minimum wage legislature.[6]
However. as positive economics continuously progressed, economist' that believe in normative concept tended to disconnect from their positive beliefs.[10]
Philosophy[edit]
According to Friedman,[6] the ultimate goal of a positive science is to develop a "theory" or "hypothesis" that makes meaningful predictions of a phenomenon that is not yet examined. Friedman states that sometimes it is a ""language" that designed to promote "systematic and organised methods of reasoning" and in part, "It is a body of substantive hypotheses designed to abstract essential features of complex reality."[6]
In Uskali Mäki's book "The Methodology of Positive Economics : Reflections on the Milton Friedman Legacy",[11] he suggests that the theory of positive economics consists of "complex intermixture of two elements".
The methodological basis for positive/normative distinctions is rooted in the fact-value distinction in philosophy. The principal proponents of such distinctions originate with David Hume and G. E. Moore. Hume defined a 'matter of fact' as something that could be directly perceived with one of the five senses.[7] However, current positivist science now poses facts that cannot be verified in this manner.[7] John Stuart Mill made use of Hume's fact-value distinction to define the science and art of economics in A System of Logic.[7]
The logical basis of such a relation as a dichotomy has been disputed in philosophical literature. Such debates are reflected in discussion of positive science.
Criticism[edit]
Since its inception as a discipline, economics has been criticized for failing to adequately separate its scientific and non-scientific aspects.[7]
Critics such as Gunnar Myrdal (1954) and proponents of Feminist Economics such as Julie A. Nelson,[12] Geoff Schneider and Jean Shackelford,[13] and Diana Strassmann[14] dispute the idea that economics can be completely neutral and agenda-free.
Nelson argues that many of the current failings of economics are a result of it not being objective enough. Rather than being value-free, many of its perspectives on "subject, model, method and pedagogy" are bound up in a "masculine-gendered" approach.[12]
Schnedier and Shackelford in Ten Principles of Feminist Economics take issue with the definition of economics as a value-free, positive science. They propose that values play a role in all levels of economic analysis and that the types of questions that economists choose to investigate are influenced by ideological systems. For example, the statement "A country's standard of living depends on its ability to produce goods and services" relies on the ideologically-motivated assumption that GDP per capita is the most useful indicator of standard of living.[13]
Hilary Putnam has also criticized the very foundation of the positive/normative dichotomy from a linguistic perspective, arguing that it is not possible to separate "value judgments from statements of facts".[7]
Moreover, Lewis Hill critiques positive economics in his work "A Critique of Positive Economics".[15] According to Hill, there are two important aspects of positive economics: Denial of normative value and economic epistemology. Hill criticizes the methodology of positive economics. There is lack of ethical considerations as positive economics targets to be value-neutral.