Thanks for all of your thoughts on this! I can speak a little to the question about metrics:
I’m curious if you’ve given any thought to dollar-weighted attrition, where you look at the total amount of money donated in year N divided by the total amount of money pledged in year N-1 for year N. (It’s possible this number could be above 100% if people underestimate how much they’ll donate.)
This isn’t something we’ve used in our impact evaluations, since we are missing donation data from around two fifths of our members. This calculation would give us a lower bound % of pledged money that was donated in a given year, but wouldn’t give us information about the missing data. For what it’s worth, I’ve had a quick look, and for the year 2014, 65% of the donations pledged for the year were recorded in My Giving.
It’d be good to hear more about your ideas for a survival analysis. If you have the time feel free to get in touch (alison[dot]woodman[at]givingwhatwecan.org)
Hi Peter,
Thanks for all of your thoughts on this! I can speak a little to the question about metrics:
This isn’t something we’ve used in our impact evaluations, since we are missing donation data from around two fifths of our members. This calculation would give us a lower bound % of pledged money that was donated in a given year, but wouldn’t give us information about the missing data. For what it’s worth, I’ve had a quick look, and for the year 2014, 65% of the donations pledged for the year were recorded in My Giving.
It’d be good to hear more about your ideas for a survival analysis. If you have the time feel free to get in touch (alison[dot]woodman[at]givingwhatwecan.org)