Friday afternoon, the Centers for Disease Control made public a study conducted by the department to quantify the effects of certain policies on COVID-19 transmission. Mask mandates were shown to curtail the growth in daily COVID-19 cases by 0.5% to 1.9% after they were implemented. Allowing restaurants to host dining on their premises had a smaller effect.
First, the data on mask effectiveness.
The study’s authors say that once you take compounding into effect, the decline is more significant than it first appears. The CDC will continue to recommend mask mandates. Critics have been quick to point out that Dr. Robert Redfield, who headed the agency from 2018 until this January, once said in Senate testimony that masking would probably prove more effective than a vaccine.
The question isn’t whether masks work, but just how much they work? The difference for Houghton County amounts to one case avoided roughly every 10 days using recent activity levels, given the data presented. Weigh that against the strife within the community that has bubbled over since summer, with neighbors pitted against neighbors, often due to religious beliefs. There have been real costs from the exaggeration of mask efficacy by public health officials at the state and federal level.
Potential negative effects of allowing dining at restaurants were also studied.
For 40 days after dining returned, there is no statistical evidence of an increase in transmission. Looking at the period from 81-100 days, the data is marginal. The p-value, which tells us if we can reject the null hypothesis (no effect), is barely below its required threshold. The confidence interval for growth in cases has a lower bound of 0.0%. While the hypothesis seems to be on firmer ground between 41 and 60 days after dining is allowed, looking at the whole picture shows significant noise.