"Human Action: A Treatise on Economics" is the first comprehensive treatise on economics written by a leading member of the modern Austrian school of economics. Von Mises contribution was very simple, yet at the same time extremely profound: he pointed out that the whole economy is the result of what individuals do. Individuals act, choose, cooperate, compete, and trade with one another. In this way Mises explained how complex market phenomena develop. Mises did not simply describe economic phenomena - prices, wages, interest rates, money, monopoly and even the trade cycle - he explained them as the outcomes of countless conscious, purposive actions, choices, and preferences of individuals, each of whom was trying as best as he or she could under the circumstances to attain various wants and ends and to avoid undesired consequences. Hence the title Mises chose for his economic treatise, "Human Action."