Originally Posted by AmateurFlix

If you're trying to measure it in relative terms then there are too many other factors to consider it properly. Gross domestic product being one, expenses being another (which he hasn't mentioned). Now should you consider population of the donors or not? Should you consider the other economic trends (recession, growth) of the donors or not? All these factors end up muddying up the results so much that even the two example methods this Roodman gave give two different results.

OK, I'm done here for the night.

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