How far a given human being is from fresh hot bacon. This index value is an indicator of quality of life in both first and third world countries.
the BPI is the product of a number of variables
1. distance travel needed
2. modes of travel needed
3. local, relative cost of bacon
4. time required for bacon preparation
5. quality of bacon available
6. risks to be undertaken to achieve the bacon
I'm in Denny's right now bro, my Bacon Proximity Index (BPI) is at the absolute maximum value known in the universe.