1) "The Philosophy of Economics is the branch of philosophy which studies philosophical issues relating to economics. It can also be defined as the branch of economics which studies its own foundations and status as a moral science." Source and further information: http://en.wikipedia.org/wiki/Philosophy_of_economics 2) "Political economy originally was the term for studying production, buying and selling, and their relations with law, custom, and government. Political economy originated in moral philosophy (e.g. Adam Smith was Professor of Moral Philosophy at the University of Glasgow[1]), it developed in the 18th century as the study of the economies of states — polities, hence political economy. In contradiction to the theory of the Physiocrats, wherein land was the source of all wealth, some political economists proposed the labour theory of value (introduced by John Locke, developed by Adam Smith, and later by Karl Marx), according to which labour is the true source of value. Many political economists also noted the accelerating development of technology, whose role in economic and social relations was important (Joseph Schumpeter). In late nineteenth century, the term "political economy" was generally replaced by the term economics, used by those seeking to place the study of economy upon mathematical and axiomatic bases, rather than the structural relationships of production and consumption (cf. marginalism, Alfred Marshall)." Source and further information: http://en.wikipedia.org/wiki/Political_economy "Economic policy refers to the actions that governments take in the economic field. It covers the systems for setting interest rates and government deficit as well as the labour market, national ownership, and many other areas of government. Such policies are often influenced by international institutions like the International Monetary Fund or World Bank as well as political beliefs and the consequent policies of parties." Source and further information: http://en.wikipedia.org/wiki/Economic_policy 3) "Economic history is the study of how economic phenomena evolved in the past. Analysis in economic history is undertaken using a combination of historical methods, statistical methods and by applying economic theory to historical situations. The topic includes business history and overlaps with areas of social history such as demographic history and labor history. Quantitative economic history is also referred to as cliometrics." Source and further information: http://en.wikipedia.org/wiki/Economic_history "The history of economic thought deals with different thinkers and theories in the field of political economy and economics from the ancient world to the present day. Although the British philosopher Adam Smith is generally considered the father of economics, his ideas built upon a considerable body of work from predecessors in the eighteenth century. They in turn were grappling with wisdom received from centuries before and attempting to apply it to a modern setting." Source and further information: http://en.wikipedia.org/wiki/History_of_economic_thought 4) "Financial economics is the branch of economics concerned with "the allocation and deployment of economic resources, both spatially and across time, in an uncertain environment" [1]. It is additionally characterised by its "concentration on monetary activities", in which "money of one type or another is likely to appear on both sides of a trade" [2]. The questions within Financial economics are typically framed in terms of "time, uncertainty, options and information" " Source and further information: http://en.wikipedia.org/wiki/Financial_economics 5) "Econophysics is an interdisciplinary research field, applying theories and methods originally developed by physicists in order to solve problems in economics, usually those including uncertainty or stochastic elements and nonlinear dynamics. Its application to the study of financial markets has also been termed statistical finance referring to its roots in statistical physics. Basic tools of econophysics are probabilistic and statistical methods often taken from statistical physics. Physics models that have been applied in economics include percolation models, chaotic models developed to study cardiac arrest, and models with self-organizing criticality as well as other models developed for earthquake prediction.[1] Moreover, there have been attempts to use the mathematical theory of complexity and information theory, theories developed by many scientists among whom Murray Gell-Mann and Claude E. Shannon, respectively. Since economic phenomena are the result of the interaction among many heterogeneous agents, there is an analogy with statistical mechanics, where many particles interact; but it must be taken into account that the properties of human beings and particles significantly differ. There are, however, various other tools from physics that have so far been used with mixed success, such as fluid dynamics, quantum mechanics (including so-called quantum economy), and the path integral formulation of statistical mechanics." Source and further information: http://en.wikipedia.org/wiki/Econophysics