| Growth assumes that older posters continue to post, which both according to TFA and my own analysis isn't true. In my own analysis, comments in a thread have a recent-user bias and roughly 30-40% of an article's comments will come from the last 3-4 years of users. I found this to hold true for many large threads over the past 5 years, though I haven't yet exhaustively demonstrated this yet simply because I don't do HN analysis that often. What that means practically is that the folks who post on this site are constantly changing. I also, generally, find that the most contentious threads on this site tend to have a relatively stronger recency bias among its posters. By that regard, eternal September is ever present: the posts on this site weigh toward recent posters. I'd be curious to see if that effect can be explained by throwaways and sock puppet posters but I'm not sure of any reliable way to identify those especially as historic karma counts aren't kept for users. While I have more robust models that work a lot better, a very simple method I've found is that the more recent the upper percentiles of posters are on a thread, the less I will like it: to me Eternal September is here. Of course my user here is ancient from 2009. The numbers just quantify that there's been a change in audience since I joined, a wholly unsurprising fact. |
basically, quality(new user + time) = quality(old user), as long as the proportion of new users/old users remains small. of course it's subjective as to where you put this value though. i just think it hasn't been reached yet here.