What is risk decomposition?
The purpose of risk decomposition is to determine how portfolio risk depends from its consti- tuting assets. Given an asset in a portfolio one may ask two questions: 1. How much portfolio risk can I attribute to this asset?
What is variance decomposition used for?
Variance decomposition enables you to determine how much of the variability in dependent variable is lagged by its own variance. In addition, it shows you which of the independent variables is “stronger” in explaining the variability in the dependent variables over time.
What is portfolio risk decomposition?
The Method of Risk Decomposition To create a portfolio risk decomposition, we take the index returns (excess of the risk-free rate) of our target portfolio and regress them on a number of common risk factors, including: Global equity returns.
Is the decomposition of the total variance unique?
The decomposition is not unique. It depends on the order of the conditioning in the sequential decomposition. and the explained component of the variance divided by the total variance is just the square of the correlation between Y and X; i.e., in such cases,
Which is the formula for the law of total variance?
In probability theory, the law of total variance or variance decomposition formula or conditional variance formulas or law of iterated variances also known as Eve’s law, states that if X and Y are random variables on the same probability space, and the variance of Y is finite, then. Var ( Y ) = E [ Var ( Y ∣ X ) ] + Var ( E [ Y ∣ X ] ) .
What are the unexplained and explained components of variance?
In language perhaps better known to statisticians than to probability theorists, the two terms are the “unexplained” and the “explained” components of the variance respectively (cf. fraction of variance unexplained, explained variation ).