Financial economics in the context of Economic model

An economist is a professional and practitioner in the social science discipline of economics.

The individual may also study, develop, and apply theories and concepts from economics and write about economic policy. Within this field there are many sub-fields, ranging from the broad philosophical theories to the focused study of minutiae within specific markets, macroeconomic analysis, microeconomic analysis or financial statement analysis, involving analytical methods and tools such as econometrics, statistics, economics computational models, financial economics, regulatory impact analysis and mathematical economics.

Epistemology of finance is a broad field of study that aims at providing a conceptual framework(s) for the interpretation of mathematical models in finance as well as the study of their possible limitations, in order to determine the epistemological standards according to which financial theory should be assessed against any associated empirical reality. A key problem is to what extent the combination of self-reference and adaption (reflexivity) undermine the stability, uniqueness, and usefulness of predictive models in finance and economics.

Within applied financial disciplines (which subsume financial economics, quantitative, and statistical finance) a single common assumption is pervasive; namely, that capital markets, being social systems, adhere sufficiently to epistemic norms. It has been argued that the use of incorrect epistemological assumptions is pervasive in financial economics and economics. These assumed epistemic norms carry with them a priori the necessity of unique, well-defined causal chains that can be meaningfully extracted from data. Both heterodox and mainstream economics retain the view that causality remains relevant as a formalism and that models remain sufficiently stable and unique (including under self-reference) and for this reason typically characterize empirical finance as science.

The efficient-market hypothesis (EMH) is a hypothesis in financial economics that states that asset prices reflect all available information. A direct implication is that it is impossible to "beat the market" consistently on a risk-adjusted basis since market prices should only react to new information.

Because the EMH is formulated in terms of risk adjustment, it only makes testable predictions when coupled with a particular model of risk. As a result, research in financial economics since at least the 1990s has focused on market anomalies, that is, deviations from specific models of risk.

In financial economics, a liquidity crisis is an acute shortage of liquidity. Liquidity may refer to market liquidity (the ease with which an asset can be converted into a liquid medium, e.g. cash), funding liquidity (the ease with which borrowers can obtain external funding), or accounting liquidity (the health of an institution's balance sheet measured in terms of its cash-like assets). Additionally, some economists define a market to be liquid if it can absorb "liquidity trades" (sale of securities by investors to meet sudden needs for cash) without large changes in price. This shortage of liquidity could reflect a fall in asset prices below their long run fundamental price, deterioration in external financing conditions, reduction in the number of market participants, or simply difficulty in trading assets.

The above-mentioned forces mutually reinforce each other during a liquidity crisis. Market participants in need of cash find it hard to locate potential trading partners to sell their assets. This may result either due to limited market participation or because of a decrease in cash held by financial market participants. Thus asset holders may be forced to sell their assets at a price below the long term fundamental price. Borrowers typically face higher loan costs and collateral requirements, compared to periods of ample liquidity, and unsecured debt is nearly impossible to obtain. Typically, during a liquidity crisis, the interbank lending market does not function smoothly either.

Capital formation is a concept used in macroeconomics, national accounts and financial economics. Occasionally it is also used in corporate accounts. It can be defined in three ways:

• It is a specific statistical concept, also known as net investment, used in national accounts statistics, econometrics and macroeconomics. In that sense, it refers to a measure of the net additions to the (physical) capital stock of a country (or an economic sector) in an accounting interval, or, a measure of the amount by which the total physical capital stock increased during an accounting period. To arrive at this measure, standard valuation principles are used.
• It is used also in economic theory, as a modern general term for capital accumulation, referring to the total "stock of capital" that has been formed, or to the growth of this total capital stock.
• In a much broader or vaguer sense, the term "capital formation" has in more recent times been used in financial economics to refer to savings drives, setting up financial institutions, fiscal measures, public borrowing, development of capital markets, privatization of financial institutions, development of secondary markets. In this usage, it refers to any method for increasing the amount of capital owned or under one's control, or any method in utilising or mobilizing capital resources for investment purposes. Thus, capital could be "formed" in the sense of "being brought together for investment purposes" in many different ways. This broadened meaning is not related to the statistical measurement concept nor to the classical understanding of the concept in economic theory. Instead, it originated in credit-based economic growth during the 1990s and 2000s, which was accompanied by the rapid growth of the financial sector, and consequently the increased use of finance terminology in economic discussions.

Applied economics is the application of economic theory and econometrics in specific settings. As one of the two sets of fields of economics (the other set being the core), it is typically characterized by the application of the core, i.e. economic theory and econometrics to address practical issues in a range of fields including demographic economics, labour economics, business economics, industrial organization, agricultural economics, development economics, education economics, engineering economics, financial economics, health economics, monetary economics, public economics, and economic history. From the perspective of economic development, the purpose of applied economics is to enhance the quality of business practices and national policy making.

The process often involves a reduction in the level of abstraction of this core theory. There are a variety of approaches including not only empirical estimation using econometrics, input-output analysis or simulations but also case studies, historical analogy and so-called common sense or the "vernacular". This range of approaches is indicative of what Roger Backhouse and Jeff Biddle argue is the ambiguous nature of the concept of applied economics. It is a concept with multiple meanings. Among broad methodological distinctions, one source places it in neither positive nor normative economics but the art of economics, glossed as "what most economists do".

In financial economics, asset pricing refers to the formal development of the principles used in pricing, together with the resultant models. The treatment inheres the interrelated paradigms of general equilibrium asset pricing and rational asset pricing, the latter corresponding to risk neutral pricing.

Investment theory, which is near synonymous, encompasses the body of knowledge used to support the decision-making process of choosing investments, and the asset pricing models are then applied in determining the asset-specific required rate of return on the investment in question, and for hedging.