Introducing PBI, Party Brand Index (Updated)

I have been working on (with some much appreciated help from pl515) a concept I'm calling PBI or Party Brand Index, as a replacement for PVI.  PVI (Partisan Voting Index), which is measured by averaging voting percentage from the last two presidential elections in each house district, and comparing it to how the nation as a whole voted, is a useful shorthand for understanding the liberal v. conservative dynamics of a district. But in my opinion it falls short in a number of areas. First it doesn't explain states like Arkansas or West Virginia. These states have districts who's PVI indicates a Democrat would be in a hard position to win, never the less Democrats (outside of the presidency) win quite handily. Secondly why is that the case in Arkansas but not Oklahoma with similar PVI rated districts?


Secondly PVI can miss trends as it takes 4 years to readjust. The main purpose of Party Brand Index is to give a better idea of how a candidate does not relative to how the presidential candidate did, but rather compared to how their generic PARTY would be expected to perform. I'm calling this Party Brand Index.