Base pay could be seen as a kind of flat rate. It mainly becomes relevant when it comes to attracting and retaining people. While most companies share a common approach on how to manage compensation with pay structures there still are various strategic decision to be made.
You'll find all slides here: https://armintrost.de/en/professor/digital/human-resources-strategies/
#31 Fundamentals and Strategies of Base Pay | Human Resources Strategies podcast - Listen or read transcript on Metacast