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  2. Multicollinearity - Wikipedia

    en.wikipedia.org/wiki/Multicollinearity

    [3] Damodar Gujarati writes that "we should rightly accept [our data] are sometimes not very informative about parameters of interest". [1] Olivier Blanchard quips that "multicollinearity is God's will, not a problem with OLS"; [7] in other words, when working with observational data, researchers cannot "fix" multicollinearity, only accept it.

  3. Moderation (statistics) - Wikipedia

    en.wikipedia.org/wiki/Moderation_(statistics)

    Multicollinearity tends to cause coefficients to be estimated with higher standard errors and hence greater uncertainty. Mean-centering (subtracting raw scores from the mean) may reduce multicollinearity, resulting in more interpretable regression coefficients. [4] [5] However, it does not affect the overall model fit.

  4. Analysis of covariance - Wikipedia

    en.wikipedia.org/wiki/Analysis_of_covariance

    3.1 Assumption 1: linearity of ... 4.1 Test multicollinearity. ... (the probability a significant difference is found between groups when one exists) ...

  5. Ridge regression - Wikipedia

    en.wikipedia.org/wiki/Ridge_regression

    Ridge regression is a method of estimating the coefficients of multiple-regression models in scenarios where the independent variables are highly correlated. [1] It has been used in many fields including econometrics, chemistry, and engineering. [2]

  6. Collinearity - Wikipedia

    en.wikipedia.org/wiki/Collinearity

    This means that if the various observations (X 1i, X 2i) are plotted in the (X 1, X 2) plane, these points are collinear in the sense defined earlier in this article. Perfect multicollinearity refers to a situation in which k (k ≥ 2) explanatory variables in a multiple regression model are perfectly linearly related, according to

  7. Heckman correction - Wikipedia

    en.wikipedia.org/wiki/Heckman_correction

    where D indicates employment (D = 1 if the respondent is employed and D = 0 otherwise), Z is a vector of explanatory variables, is a vector of unknown parameters, and Φ is the cumulative distribution function of the standard normal distribution. Estimation of the model yields results that can be used to predict this employment probability for ...

  8. Spurious relationship - Wikipedia

    en.wikipedia.org/wiki/Spurious_relationship

    Graphical model: Whereas a mediator is a factor in the causal chain (top), a confounder is a spurious factor incorrectly implying causation (bottom). In statistics, a spurious relationship or spurious correlation [1] [2] is a mathematical relationship in which two or more events or variables are associated but not causally related, due to either coincidence or the presence of a certain third ...

  9. Dickey–Fuller test - Wikipedia

    en.wikipedia.org/wiki/Dickey–Fuller_test

    Which of the three main versions of the test should be used is not a minor issue. The decision is important for the size of the unit root test (the probability of rejecting the null hypothesis of a unit root when there is one) and the power of the unit root test (the probability of rejecting the null hypothesis of a unit root when there is not one).