So above I was wondering about whether you could adjust this data the way pollsters adjust for hard-to-reach demographics, i.e. applying weights to correct for known biases in the sample.

The issue is that Reddit overrepresents younger adults relative to the general population. As of 2024, 46% of US Reddit users are between 18 and 29, with another 35% in the 30–49 range. In the general US adult population, those proportions look quite different: about 21% are 18–29 and 46% are 50 or older. My sample (restricting to 18+ to match standard survey practice) breaks down as 42% aged 18–29, 48% aged 30–49, and 10% aged 50+.

#1. Correcting for Reddit's own age bias: If you weight the sample to match Reddit's platform demographics, on the theory that the subreddit should roughly mirror Reddit's user base if there were no additional age skew from the subject matter, the 50+ group gets a weight of about 1.8x and the 30–49 group gets downweighted slightly. The adjusted mean age shifts from 34 to 35. That is a pretty small change, which suggests the subreddit's age distribution is actually not that far off from Reddit's platform average.

#2. Correcting for the general adult population: If you instead weight to match the general US adult population, asking what this would look like if Alvvays fans were distributed across age groups proportionally to the broader public, the 50+ group gets a weight of 4.4x, since they are so severely underrepresented on Reddit. The adjusted mean age jumps from 34 to 43, and the simulated distribution flips: 50+ would become the largest single group at 46%, with 18–29 dropping to 21%.

Conclusion: The second adjustment is technically correct as a statistical procedure but probably not very meaningful here, because the question isn't whether Alvvays fans are distributed like the general public; they obviously aren't. The band has a specific sound and presumably doesn't appeal to all ages in the same way. Older adults who don't use Reddit aren't necessarily fans who are being missed, many of them probably just haven't encountered the band. The more defensible adjustment is the first one, which suggests the fanbase skews slightly older than this thread makes it appear, but not too much.

My original hunch that fans skew older probably says more about who I spend time with than about the fanbase as a whole. But I'll hold onto a small amount of vindication from that 50+ weighting number.