Negative coefficients in regression for positive coefficient of correlation

0 votes
I am building a multiple linear regression model using python. I found the correlation coefficients between all the independent variables and the dependent variable. They were all greater than 0.5. However, the equation given by the regression model has a few negative coefficients. Why is that?
Mar 23, 2022 in Machine Learning by Dev
• 6,000 points
3,407 views

1 answer to this question.

0 votes

The situation you describe is not out of the bounds of possibility. The idea is to look at how your independent variables are related. It's possible that one of them has a negative coefficient in your linear regression if there's a high correlation between two of them.

Consider the following scenario, in which you want to forecast y given independent variables x1 and x2:
Assume y is deterministic and follows the formula y = x1 + 2 * x2.
Assume that x2 is predictable as well, and that x2 = 0.1 * x1

Then you could say y = 1.2 * x1 + 0 * x2 as well as y = 0 * x1 + 12 * x2 or y = 2 * x1 - 8 * x2 because your linear regression has an endless number of possibilities. Although there is a positive correlation between y and x2, your linear regression has a negative coefficient in this example. There isn't a single mistake or error.
That is why you should not assume that just because your linear regression model has a positive slope, there is a positive correlation between the independent and predicted variables. And, of course, you can't draw any conclusions about causation based on your findings.

Supercharge Your Skills with Our Machine Learning Course!

answered Mar 25, 2022 by Nandini
• 5,480 points

Related Questions In Machine Learning

0 votes
1 answer
0 votes
1 answer

If both negative and positive skewness are present in data set,then how it can be removed??

Hi@shama, It depends on your use case. If ...READ MORE

answered Dec 8, 2020 in Machine Learning by MD
• 95,460 points
742 views
0 votes
0 answers

Limitations of Regression in Machine Learning?

what happens when you want to do ...READ MORE

Feb 28, 2022 in Machine Learning by Dev
• 6,000 points
354 views
0 votes
2 answers
+1 vote
2 answers

how can i count the items in a list?

Syntax :            list. count(value) Code: colors = ['red', 'green', ...READ MORE

answered Jul 7, 2019 in Python by Neha
• 330 points

edited Jul 8, 2019 by Kalgi 4,391 views
0 votes
1 answer
0 votes
1 answer

What is the difference between Coefficient of Regression and Elasticity

It is questionable. I'll simplify the model ...READ MORE

answered Apr 4, 2022 in Machine Learning by Nandini
• 5,480 points
734 views
0 votes
1 answer

Calculate the probability in R for sum of two dice rolls

By converting the outer values to a ...READ MORE

answered Apr 4, 2022 in Machine Learning by Nandini
• 5,480 points
2,039 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP