In psychoanalysis and behaviorism, it is used for the personal way a given individual reacts, perceives and experiences a common situation: a certain dish made of meat may cause nostalgic memories in one person and disgust in another. These reactions are called idiosyncratic. Economics In portfolio theory, risks of price changes due to the unique circumstances of a specific security, as opposed to the overall market, are called "idiosyncratic risks". This specific risk, also called unsystematic, can be nulled out of a portfolio through diversification. Pooling multiple securities means the specific risks cancel out. In complete markets, there is no compensation for idiosyncratic risk—that is, a security's idiosyncratic risk does not matter for its price. For instance, in a complete market in which the capital asset pricing model holds, the price of a security is determined by the amount of systematic risk in its returns. Net income received, or losses suffered, by a landlord from renting of one or two properties is subject to idiosyncratic risk due to the numerous things that can happen to real property and variable behavior of tenants. According to one macroeconomic model including a financial sector, hedging idiosyncratic risk can be self-defeating as it leads to higher systemic risk, as it takes on more leverage. This makes the system less stable. Thus, while securitisation in principle reduces the costs of idiosyncratic shocks, it ends up amplifying systemic risks in equilibrium. In econometrics, "idiosyncratic error" is used to describe error—that is, unobserved factors that impact the dependent variable—from panel data that both changes over time and across units (individuals, firms, cities, towns, etc.). See also Eccentricity (behavior) References External links Allergology Deviance (sociology) Inborn errors of metabolism Medical terminology Effects of external causes