University group members are mostly undergraduates, meaning they are younger than ~22. This implies that they would have been younger than 18 in 2017, and there was almost no one like that on the 2017 survey. And they would have been under 16 in 2015, although I donât think we have data going back that far. I can think of one or two people who might have gotten involved as 15-year-olds in 2015, but it seems quite rare. Is there something Iâm missing?
Iâm not sure where you are disagreeing, because I agree that many people founding groups since 2015 will in fact have joined the movement later than 2015. Indeed, as I show in the first graph in the comment youâre replying to, newer cohorts of EA are much larger than previous cohorts, and as a result most people (>60%) in the movement (or at least the EA Survey sample[^1]) by 2019 are people who joined post-2015. Fwiw, this seems like more direct evidence of growth in EA since 2015 than any of the other metrics (although concern about attrition mean that itâs not straightforward evidence that the total size of the movement has been growing, merely that weâve been recruiting many additional people since 2015).
My objection is that pointing to the continued growth in number of EA groups isnât good evidence of continued growth in the movement since 2015 due to lagginess (groups being founded by people who joined the movement in years previous). It sounds like your objection is that since we also know that some of the groups are university groups (albeit a slight minority) and university groups are probably mostly founded by undergraduates, we know that at least some of the groups founded since 2015 were likely founded by people who got into EA after 2015. I agree this is true, but think we still shouldnât point to the growth in number of new groups as a sign of growth in the movement because itâs a noisy proxy for growth in EA, picking up a lot of growth from previous years. (If we move to pointing to separate evidence that some of the people who founded EA groups probably got into EA only post 2015, then we may as well just point to the direct evidence that the majority of EAs got into EA post-2015!)
[^1]: I donât take this caveat to undermine the point very much because, if anything I would expect the EA Survey sample to under-represent newer, less engaged EAs and over-represent EAs who have been involved longer.
I think maybe I was confused about what you are saying. You said:
I think this applies to growth in local groups particularly well⌠While Iâve no doubt that many of the groups that have been founded by people who joined since 2015*, I suspect that even if we cut those people out of the data, weâd still see an increase in the number of local groups over that time frame- so we canât infer that EA is continuing to grow based on increase in local group numbers.
But then also:
Fwiw, this seems like more direct evidence of growth in EA since 2015 than any of the other metrics
In my mind, A being evidence of B means that you can (at least partially) infer B from A. But Iâm guessing you mean âinferâ to be something like âproveâ, and I agree the evidence isnât that strong.
DM: While Iâve no doubt that many of the groups that have been founded by people who joined since 2015*, I suspect that even if we cut those people out of the data, weâd still see an increase in the number of local groups over that time frame- so we canât infer that EA is continuing to grow based on increase in local group numbers.
BW: It sounds like maybe when you say âwe canât infer that EA is continuing to grow based on increase in local group numbersâ you mean âpart of the growth might be explained by things other than what would be measured by a change in number of groupsâ? (Or possibly âincreasing group numbers is evidence of growth since 2015, but not necessarily evidence of growth since, say, 2019â?)
I meant something closer to: âwe canât infer Y from X, because weâd still expect to observe X even if ÂŹY.â
My impression is still that we have been somewhat talking past each other, in the way I described in the second paragraph of my previous comment. My core claim is that we should not look at the number of new EA groups as a proxy for growth in EA, since many new groups will just be a delayed result of earlier growth in EA, (as it happens I agree that EA has grown since 2015, but weâd see many new EA groups even if it hadnât). Whereas, if I understand it, your claim seems to be that as we know that at least some of the new groups were founded by new people to EA, we know that there has been some new EA growth.
University group members are mostly undergraduates, meaning they are younger than ~22. This implies that they would have been younger than 18 in 2017, and there was almost no one like that on the 2017 survey. And they would have been under 16 in 2015, although I donât think we have data going back that far. I can think of one or two people who might have gotten involved as 15-year-olds in 2015, but it seems quite rare. Is there something Iâm missing?
Iâm not sure where you are disagreeing, because I agree that many people founding groups since 2015 will in fact have joined the movement later than 2015. Indeed, as I show in the first graph in the comment youâre replying to, newer cohorts of EA are much larger than previous cohorts, and as a result most people (>60%) in the movement (or at least the EA Survey sample[^1]) by 2019 are people who joined post-2015. Fwiw, this seems like more direct evidence of growth in EA since 2015 than any of the other metrics (although concern about attrition mean that itâs not straightforward evidence that the total size of the movement has been growing, merely that weâve been recruiting many additional people since 2015).
My objection is that pointing to the continued growth in number of EA groups isnât good evidence of continued growth in the movement since 2015 due to lagginess (groups being founded by people who joined the movement in years previous). It sounds like your objection is that since we also know that some of the groups are university groups (albeit a slight minority) and university groups are probably mostly founded by undergraduates, we know that at least some of the groups founded since 2015 were likely founded by people who got into EA after 2015. I agree this is true, but think we still shouldnât point to the growth in number of new groups as a sign of growth in the movement because itâs a noisy proxy for growth in EA, picking up a lot of growth from previous years. (If we move to pointing to separate evidence that some of the people who founded EA groups probably got into EA only post 2015, then we may as well just point to the direct evidence that the majority of EAs got into EA post-2015!)
[^1]: I donât take this caveat to undermine the point very much because, if anything I would expect the EA Survey sample to under-represent newer, less engaged EAs and over-represent EAs who have been involved longer.
I think maybe I was confused about what you are saying. You said:
But then also:
In my mind, A being evidence of B means that you can (at least partially) infer B from A. But Iâm guessing you mean âinferâ to be something like âproveâ, and I agree the evidence isnât that strong.
I meant something closer to: âwe canât infer Y from X, because weâd still expect to observe X even if ÂŹY.â
My impression is still that we have been somewhat talking past each other, in the way I described in the second paragraph of my previous comment. My core claim is that we should not look at the number of new EA groups as a proxy for growth in EA, since many new groups will just be a delayed result of earlier growth in EA, (as it happens I agree that EA has grown since 2015, but weâd see many new EA groups even if it hadnât). Whereas, if I understand it, your claim seems to be that as we know that at least some of the new groups were founded by new people to EA, we know that there has been some new EA growth.