The annual ACS definitely isn’t perfect, but it’s pretty good. (They did mess up Philly’s poverty rate a few years ago.)

And the decline is big enough that even if it is over-estimating the decline, it’s probably still a decline. And it declined last year too.

I agree that I wouldn’t rush to conclusions until we’ve got another year of data, but I also wouldn’t just hand-wave it away and assume it’s incorrect, especially in one particular direction. Maybe it’s under-estimating the decline.

But yeah, next year, if we get a decline again, and the l 3-year ACS date file shows a decline, then it’s probably a decline.