The DHS Program User Forum
Discussions regarding The DHS Program data and results
Home » Topics » Wealth Index » Not positive definite correlation matrix
Re: Not positive definite correlation matrix [message #24656 is a reply to message #24647] Wed, 15 June 2022 09:01 Go to previous message
Janet-DHS is currently offline  Janet-DHS
Messages: 779
Registered: April 2022
Senior Member
Following is a response from DHS Research & Data Analysis Director, Tom Pullum:

"Not positive definite" means that a matrix cannot be inverted because the components are too highly correlated with one another. It's equivalent to "multi-collinearity". When this happens during the construction of the wealth index with principal components analysis, I believe it is basically a judgment call how to reduce the number of variables. I don't believe there is any formal guidance on what to keep and what to drop--and I don't think it would make much difference, because multi-collinearity just means that the variables are duplicating each other.
 
Read Message
Read Message
Previous Topic: Problem with recreating Asset quintiles
Next Topic: Comparative wealth Index
Goto Forum:
  


Current Time: Wed Jul 24 16:42:31 Coordinated Universal Time 2024