Neo-classical economics has been the dominant approach in economics since the end of WWII. Prior to WWII, institutional economics enjoyed a wide following as an alternative economic methodology. Neo-classical economics is distinguished by the use of optimal decision making to model and theorize about economic activity. Decisions represent some maxima or minima of an agent's objective function subject to some constraint. Profit and utility maximization are just two variants of this approach. Neo-classical economics is often known as micro-economics or price-theory. There are, however, other forms of mico-economics and price-theory. These denotations reflect the hegemony of neo-classical economics in academia. Currently, the terrian of neo-classical economics is being challenged from many directions. Behavioral, evolutionary, experimental, computational, institutional, neo-institutional, Post-Keynesian (i.e., Keynesian), Austrian, Marxist, feminist, and Sraffian economics all, to varying degrees, represent challenges to the neo-classical paradigm.