Debunking the Generosity Index
The most frequent cited “proof” that conservatives are more charitable than liberals is the generosity index from the Catalogue for Philanthropy. I’d like to put the debunk here for general reference.
Here’s the way it works. The IRS reports for the states are assembled, and both the average AGI (total AGI divided by population. called AAGI) and average claimed deductions for charitable giving (same by population division, called AICG) are calculated. So far, so good.
Both are ranked from most to least, then the RANK of giving is subtracted from the RANK of income.
If your state has the highest average income it is impossible to have a score higher than 0, which can happen only if your state is also the highest in giving - it’s more likely to be negative. If your state has the lowest income it’s impossible to have a negative score.
Since the states that vote predominately Republican also tend to be in the lower half of the income ranking, it becomes inevitable that they’ll tend to get a better Generosity Score.
On the surface it would seem a more equitable ranking would be made by calculating each state’s AICG:AAIG ratio and ranking the results. The legitimate objection to that ratio goes even further to demonstrate how poor a measure this is.
Basically, only higher income people tend to itemize deductions and so have itemized charitable giving. As a result, the rank of ratios is remarkably similar to the rank of AAGI, allowing the claim that the rich give more of their income than the poor.
It’s a bad index, proving nothing.