Hi all! My research is on the impact of immunization coverage on child mortality in India. There is data available on different vaccines like bcg, dpt, measles, etc.(all in %). I have done PCA and then constructed an index using the PC1. I have run a simple linear regression of my y variable i.e. U5MR on the index and other explanatory variables such as sanitation,dietary intake, mother's education,etc. I am not able to figure out the interpretation of the coefficient of the index constructed as a result of the regression