When attempting to determine the effectiveness of responses to issues or the results of experiments, using a simple A-B test often yields straightforward answers to more complex problems. If we have two similar samples, a binary “Do X for sample A, and do Y for sample B” can be an easy way to see which intervention is more effective.

With COVID-19, government policy mandates have been unprecedented. As with most other countries around the world, the United States seen dramatic examples of top-down restrictions designed to protect citizens from the invisible virus – and each state has had different approaches. But have these interventions been successful? Have they saved lives? How many? Or destroyed livelihoods? Has the cure been worse than the disease?

Although the answers to these questions remain largely undetermined and are difficult to discern with a high degree of confidence, we can look at relatively similar sample populations which had substantially different policy interventions and examine the results. For this example, let’s compare COVID’s recent impact in North Dakota vs. South Dakota:

Both states share similar climate profiles, population size and densities, and overall demographics. While different in some respects, the core similarities of each state provide us with a unique opportunity to isolate policy interventions as the most significant underlying variable with the most recent wave of COVID infections.

North Dakota’s Government Response: While initially advocating for a limited government response, on November 13th, 2020 Governor Burgum signed an executive order for:

1) Mask mandates (all indoor and public settings – 30 days)
2) Bars/Restaurants 50% capacity, 150 persons. Curfew 10pm to 4am.
3) Banquets, Halls, events 25% of capacity.

These orders were eased somewhat and extended until mid-January.

South Dakota’s Government Response: Governor Noem has advocated or public advisories, protecting vulnerable populations, and championing individual liberties and awareness.

So, what were the results?

The results have been nearly identical from a practical standpoint. In isolation, it would appear North Dakota’s government interventions led to a direct reduction in COVID cases. However, the timing of the downturn in cases also happened almost exactly at the same time in South Dakota (without the restrictions).

Below are the COVID case and fatality trends for each state:

source: worldometers.info

source: data.cdc.gov

Note: The CDC cause of death data is updated on a slightly delayed basis based on the medical record reporting. As a result, the weekly death totals will likely rise to a normalized trendline for recent weeks. However, the directional trends related to cause (COVID vs. non-COVID) should remain the same.

Digging deeper into the numbers it appears the relatively small variances in cases per population, and overall case fatality rates could be largely driven by demographic differences as seen in the census numbers below:

https://www.census.gov/quickfacts/ND

https://www.census.gov/quickfacts/SD

So…Do government mask mandates and restrictions work? Given the available data, a case could be made either way. However, it is clear the results (restrictions vs. no restrictions) are similar enough to warrant a much closer look. It appears mother nature is firmly in control – despite our best efforts to mitigate the impacts through mask mandates and school/business closures and restrictions.