TL;DR: Great question! I think it mostly means that we don’t have enough data to say much about these projects. So donors who’ve made early donations to them, can register them and boost their project score.
The donor score relies on the size of the donations and their earliness in the history of the project (plus the retroactive evaluation). So the top donors in particular have made many early, big, and sometimes public grants to projects that panned out well – hence why they are top donors.
What influences the support score is not the donor score itself but the inverse rank of the donor in the ranking that is ordered by the donor score. (This corrects the outsized influence that rich donors would otherwise have, since I assume that wealth is Pareto distributed but expertise is maybe not, and is probably not correlated at quite that extreme level.)
But if a single donor has more than 90% influence on the score of a project, they are ignored, because that typically means that we don’t have enough data to score the project. We don’t want a single donor to wield so much power.
Taken together, our top donors have (by design) the greatest influence over project scores, but they are also at a greater risk of ending up with > 90% influence over the project score, especially if the project has so far not found many other donors who’ve been ready to register their donations. So the contributions of top donors are also at greater risk of being ignored until more donors confirm the top donors’ donation decisions.
Ok so the support score is influenced non-linearly by donor score. Is there a particular donor that has donated to the highest ranked 22 projects, that did not donate to the 23 or lower ranked projects?
I have graphed donor score vs rank for the top GiveWiki donors. Does this include all donors in the calculation or are there hidden donors?
Does this include all donors in the calculation or are there hidden donors?
Donors have a switch in their profiles where they can determine whether they want to be listed or not. The top three in the private, complete listing are Jaan Tallinn, Open Phil, and the late Future Fund, whose public grants I’ve imported. The total ranking lists 92 users.
But I don’t think that’s core to understanding the step down. I’ve gone through the projects around the threshold before I posted my last comment, and I think it’s really the 90% cutoff that causes it. Not a big donor who has donated to the first 22 but not to the rest.
There are plenty of projects in the tail that have also received donations from a single donor with a high score – but more or less only that so that said donor has > 90% influence over the project and will be ignored until more donors register donations to it.
Ok so the support score is influenced non-linearly by donor score.
By the inverse rank in the ranking that is sorted by the score. So the difference between the top top donor and the 2nd top donor is 1 in terms of the influence they have.
We see a massive drop in score from the 22nd to the 23rd project. Can you explain why this is occurring?
TL;DR: Great question! I think it mostly means that we don’t have enough data to say much about these projects. So donors who’ve made early donations to them, can register them and boost their project score.
The donor score relies on the size of the donations and their earliness in the history of the project (plus the retroactive evaluation). So the top donors in particular have made many early, big, and sometimes public grants to projects that panned out well – hence why they are top donors.
What influences the support score is not the donor score itself but the inverse rank of the donor in the ranking that is ordered by the donor score. (This corrects the outsized influence that rich donors would otherwise have, since I assume that wealth is Pareto distributed but expertise is maybe not, and is probably not correlated at quite that extreme level.)
But if a single donor has more than 90% influence on the score of a project, they are ignored, because that typically means that we don’t have enough data to score the project. We don’t want a single donor to wield so much power.
Taken together, our top donors have (by design) the greatest influence over project scores, but they are also at a greater risk of ending up with > 90% influence over the project score, especially if the project has so far not found many other donors who’ve been ready to register their donations. So the contributions of top donors are also at greater risk of being ignored until more donors confirm the top donors’ donation decisions.
Ok so the support score is influenced non-linearly by donor score. Is there a particular donor that has donated to the highest ranked 22 projects, that did not donate to the 23 or lower ranked projects?
I have graphed donor score vs rank for the top GiveWiki donors. Does this include all donors in the calculation or are there hidden donors?
Donors have a switch in their profiles where they can determine whether they want to be listed or not. The top three in the private, complete listing are Jaan Tallinn, Open Phil, and the late Future Fund, whose public grants I’ve imported. The total ranking lists 92 users.
But I don’t think that’s core to understanding the step down. I’ve gone through the projects around the threshold before I posted my last comment, and I think it’s really the 90% cutoff that causes it. Not a big donor who has donated to the first 22 but not to the rest.
There are plenty of projects in the tail that have also received donations from a single donor with a high score – but more or less only that so that said donor has > 90% influence over the project and will be ignored until more donors register donations to it.
By the inverse rank in the ranking that is sorted by the score. So the difference between the top top donor and the 2nd top donor is 1 in terms of the influence they have.
Meta question: is the above picture too big?
It displays well for me!