The study of purposeful human action
  • Economics - Study of the production, distribution and consumption of goods and services

Reference

Glossary: Praxeology, by Percy L. Greaves, Jr., Mises Made Easier, 1974
"(from the Greek, Praxis, action, habit or practice; logia, doctrine, theory or science). The science or general theory of (conscious or purposeful) human action. Mises defines action as 'the manifestation of a man's will.' Accordingly, he considers the use of the adjectives 'conscious or purposeful' to be redundant. Praxeology is a manifestation of the human mind and deals with the actions open to men for the attainment of their chosen ends. Praxeology starts from the a priori category of action and then develops the full implications of such action. Praxeology aims at knowledge valid for all instances in which the conditions exactly correspond to those implied in its assumptions and inferences. Its statements and propositions are not derived from experience, but are antecedent to any comprehension of historical facts."
Praxeology - Wikipedia, the free encyclopedia
"Praxeology is the deductive study of human action based on the action-axiom. The most common use of the term is in connection with the Austrian School of economics. The term was coined by Austrian school economist Ludwig von Mises. ..."