if they normalized the budget such that extra things not purchased in previous years is not taken into account, it could be used as a personal inflation measure. Normalizing the budget means you remove any life-style creep that gets in.

This way, you can look at your salary, and determine whether you're gaining income above your own inflation, or not.

Normalizing the budget that way would seem to be incredibly difficult at a personal level.

If I started buying a better cut of steak or more hamburger and less ramen than last year, would I really be able to tease out that difference without an insane amount of record keeping/data entry?