Scientific realism considers that acquiring knowledge about the external world is possible and the goal of scientific research is to discover the truth. From the point of view of instrumentalism, as the most important anti-realism version of this philosophy, theories are merely useful instruments which scientists make for scientific goals such as establishing order and prediction. The most important challenge between these two camps is about unobservable identities invented by (such theories as electrons and quarks). Scientific realists believe that these identities do exist and act, according to what their invented theories say. But form the instrumentalists' view, scientists' remarks about unobservable identities could not be taken as true or false.
In economics, as in other sciences, there are issues related to instrumentalism and realism, but - unlike the philosophy of science – the approaches do not appose each other. Friedman's instrumentalism states that the only appropriate test for an economic theory is its success in predicting phenomena. Friedman's depicted perspective of economics, in spite of its being hopeful, is never realized since economics has not been able to prepare reliable and accurate predictions. On the other hand, until recent decades realism has not had place in the methodology of economics. Since two decades ago, two distinct realistic programs have come into the literature of the methodology of economics. Uskali Mäki and Tony Lawson are the designers of these two programs.
Moghadam, V., & Vaez, M. (2009). Realism and Instrumentalism in the
Methodology of Economics. Methodology of Social Sciences and Humanities, 15(58), 33-62.
MLA
Vahid Moghadam; Mohammad Vaez. "Realism and Instrumentalism in the
Methodology of Economics". Methodology of Social Sciences and Humanities, 15, 58, 2009, 33-62.
HARVARD
Moghadam, V., Vaez, M. (2009). 'Realism and Instrumentalism in the
Methodology of Economics', Methodology of Social Sciences and Humanities, 15(58), pp. 33-62.
VANCOUVER
Moghadam, V., Vaez, M. Realism and Instrumentalism in the
Methodology of Economics. Methodology of Social Sciences and Humanities, 2009; 15(58): 33-62.
)