<P> Positive economics (as opposed to normative economics) is the branch of economics that concerns the description and explanation of economic phenomena . It focuses on facts and cause - and - effect behavioral relationships and includes the development and testing of economics theories . An earlier term was value - free (German: wertfrei) economics . </P> <P> Positive economics as science, concerns analysis of economic behavior . A standard theoretical statement of positive economics as operationally meaningful theorems is in Paul Samuelson's Foundations of Economic Analysis (1947). Positive economics as such avoids economic value judgements . For example, a positive economic theory might describe how money supply growth affects inflation, but it does not provide any instruction on what policy ought to be followed . </P> <P> Still, positive economics is commonly deemed necessary for the ranking of economic policies or outcomes as to acceptability, which is normative economics . Positive economics is sometimes defined as the economics of "what is", whereas normative economics discusses "what ought to be". The distinction was exposited by John Neville Keynes (1891) and elaborated by Milton Friedman in an influential 1953 essay . </P> <P> The methodological basis for a positive / normative distinction has its roots in the fact - value distinction in philosophy, the principal proponents of such distinctions being David Hume and G.E. Moore . The logical basis of such a relation as a dichotomy has been disputed in the philosophical literature . Such debates are reflected in discussion of positive science and specifically in economics, where critics, such as Gunnar Myrdal (1954), and proponents of Feminist Economics such as Julie A. Nelson, Geoff Schneider and Jean Shackelford, and Diana Strassmann, dispute the idea that economics can be completely neutral and agenda - free . </P>

Who said economics is sometimes positive science and sometimes normative science