Logging into Los Angeles County’s COVID-19 data portal, the first thing that you see is a bright yellow banner:

“DISCLAIMER: The lower number of cases are, in part, due to lab result reporting delays in the State electronic lab system. The number of cases is expected to increase in the coming days once the data becomes available. The hospitalization data is also incomplete due to changes in reporting requirements from the U.S. Department of Health and Human Services (HHS).”

Each day, Los Angeles County reports a total number of new cases and new deaths. What they don’t tell you is that those are old data. For instance, on 7/23/2020 they reported 2014 new cases and 49 deaths. Readers are left with the impression that that is the total number for that day. Instead, those are spread across many previous days – some perhaps as long as three weeks ago. The actual numbers (as of today) are 366 cases and 18 deaths. These will no doubt climb far higher as lab results trickle in – more likely over weeks than days.

The fact that we are experiencing reporting delays of this magnitude in late July is beyond infuriating. But moral outrage aside, it also leaves us with essentially useless data.

Below is the “current” epidemic curve for cases in Los Angeles County. A couple of patterns are clear: