Mathematics and Statistics 11(1): 51-64, 2023
DOI: 10.13189/ms.2023.110106
http://www.hrpub.org
Raise Estimation: An Alternative Approach in The
Presence of Problematic Multicollinearity
Jinse Jacob, R. Varadharajan
*
Department of Mathematics, SRM Institute of Science and Technology, India
Received August 8, 2022; Revised November 21, 2022; Accepted December 22, 2022
Cite This Paper in the following Citation Styles
(a): [1] Jinse Jacob, R. Varadharajan, ”Raise Estimation: An Alternative Approach in The Presence of Problematic Multicollinearity,” Mathematics and
Statistics, Vol.11, No.1, pp. 51-64, 2023. DOI: 10.13189/ms.2023.110106
(b): Jinse Jacob, R. Varadharajan, (2023). Raise Estimation: An Alternative Approach in The Presence of Problematic Multicollinearity. Mathematics and
Statistics, 11(1), 51-64. DOI: 10.13189/ms.2023.110106
Copyright ©2023 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of
the Creative Commons Attribution License 4.0 International License
Abstract When adopting the Ordinary Least Squares
(OLS) method to compute regression coefficients, the results
become unreliable when two or more predictor variables are
linearly related to one another. The confidence interval of the
estimates becomes longer as a result of the increased variance
of the OLS estimator, which also causes test procedures to
have the potential to generate deceptive results. Additionally,
it is difficult to determine the marginal contribution of the
associated predictors since the estimates depend on the other
predictor variables that are included in the model. This makes
the determination of the marginal contribution difficult. Ridge
Regression (RR) is a popular alternative to consider in this
scenario; however, doing so impairs the standard approach for
statistical testing. The Raise Method (RM) is a technique that
was developed to combat multicollinearity while maintaining
statistical inference. In this work, we offer a novel approach
for determining the raise parameter, because the traditional
one is a function of actual coefficients, which limits the
use of Raise Method in real-world circumstances. Using
simulations, the suggested method was compared to Ordinary
Least Squares and Ridge Regression in terms of its capacity to
forecast, stability of its coefficients, and probability of obtain-
ing unacceptable coefficients at different levels of sample size,
linear dependence, and residual variance. According to the
findings, the technique that we designed turns out to be quite
effective. Finally, a practical application is discussed.
Keywords Multicollinearity, OLS, Ridge Regression,
Raise Regression, VIF
1 Introduction
A typical linear regression model is
y = Xβ + ε (1)
where y denotes a n×1 vector of observations on the response
variable, X is a n × p (n ≥ p) matrix of observations on the
predictor variables, β is a p × 1 vector of unknown regression
coefficients to be estimated and ε is a n × 1 vector of residual
such that E(ε)=0 and E(εε
T
)= σ
2
I
n
, where I
n
denotes the
identity matrix of order n. Then one can apply Ordinary Least
Squares (OLS) method to estimate the unknown parameters,
and the corresponding estimate is
β =
(
X
T
X
)
-1
X
T
y (2)
And the corresponding variance of the estimator is
V (
β) =
(
X
T
X
)
-1
σ
2
(3)
It can be seen from equations (2) and (3) that when two or more
predictor variables are perfectly linearly related, the estimation
becomes impossible and the variance is indeterminate. Even if
the interdependency is very high, which may not be perfect, un-
desirable results will be obtained. This problem is called mul-
ticollinearity. Ragnar Frisch was the one who coined the word
”multicollinearity” [1]. It is a serious threat to proper specifica-
tion and the effective estimation of the structural relationship.
As the relationship between variables increases, whether it is in
the positive or negative direction, the standard error of the re-
gression coefficients increases. i.e., even though the OLS pro-
cedure gives unbiased estimates, they become unstable. Due
to this, the confidence intervals become wider, test procedures
lead to misleading results, unexpected signs in the coefficients,