A fairly complete analysis can be found in the following link, however, this is only ONE writer's opinion... so do additional research.
Why did God love Jacob and hate Esau (Malachi 1:3; Romans 9:13)?
A very good place to do a scriptural study for research is the entire content of
Malachi 1-4 (KJV) or for easier understanding in English, use
Malachi 1-4 (NLT). Enjoy...