Patterns: Visits drop drastically for the whole month of December 2019

Hello dear SafeGraph community,

I found that the number of total daily visits (US) drops drastically for several business types, e.g. Restaurants and other Eating Places (NAICS Code 7225) as can be seen in the two plots below. That the number of visits drops after March 2020 is clear (due to the Covid pandemic), but why for the whole month of December 2019? Has there been some data adjustments or so? I have checked the release notes of that month, but didn’t find any hint; the number of devices seen stays stable over the whole time period.

I would greatly appreciate any hint about this issue !

There have been no data adjustments for that period that I know of. If you’ve checked the stability of the devices in the panel, then the only other thing I can think of is perhaps something is going on in the way you’ve ingested that month’s data file (perhaps missing rows?).

This is not something other people have reported unfortunately so it does not seem widespread.