Blog Post – Peaking COVID: When Will the Country See a Decrease in Cases?

Written by Robert Richards, Ph.D. and David Muhlestein, Ph.D., JD

The global COVID-19 pandemic is the largest public health crisis in generations. Life as we know it, from macroeconomic conditions all the way down to personal daily life, has been impacted significantly (to put it lightly). As the pandemic has now been with us for months, it is natural that policy-makers and private citizens alike are all asking, “when will this be over?”

A white paper released last week showed that non-pharmaceutical interventions in response to COVID-19 have significantly “flattened the curve,” but as pointed out in that paper, we are not out of the woods yet. It is now extremely important to plan to reopen the economy and society in a way that will not lead to a resurgence of COVID-19. Today, we released a new analysis of our progress to date in slowing the spread of COVID-19 and also give our thoughts on how to monitor the disease. Although the nation as a whole is not ready to reopen en masse, some regions of the country may be ready for at least a partial reopening.

As described in more detail in today’s white paper, it is important to consider the growth rate and effective reproduction number (Rt) of COVID-19 on an ongoing basis. Our COVID-19 burden projections are based on a calculation of growth rate, which means we can comment on the growth rates for specific counties, metropolitan areas, and states, in addition to the nation. We are also able to provide our estimate of Rt based on that growth rate. Our estimates are based on a seven-day rolling average, so multiple days of actual drops in active cases are necessary for our estimates to show a decline. We do this to remove the volatility in the data from varied reporting cycles and other data inconsistencies, providing a more accurate picture of the current trajectory of COVID-19.

National Effective Reproduction Rate Estimate, 3/25 – 4/26

The figure above shows our estimate of Rt for the nation as a whole. When Rt is below 1, COVID-19 is in decline. As a country, we have not yet crossed that threshold. However, this national view masks significant variation across states and local communities.

Percent of Metropolitan Areas with Decreasing COVID-19 Cases

The second figure shows the percent of metropolitan and micropolitan areas (there are 954 in total) that are experiencing declining cases. Generally, this has been trending upward, meaning that over time more communities are slowing the spread of COVID-19. However, as the last few days of data show, it is possible for communities to revert back to increasing active cases. Such a reversal means that another peak may materialize at some point in the future. Our projections, updated daily and shared publicly at, can help ascertain the current trajectories in specific counties, metropolitan areas, and states.

It is crucial for policy-makers at all levels to monitor conditions in communities and make decisions about reopening on a case-by-case basis. That effort requires good data, so we also recommend policy-makers and others continue to focus on ramping up testing, especially of random samples of the population.

While we have made significant progress as a country, we are far from putting COVID-19 behind us. We must continue to monitor conditions and make informed decisions based on actionable data, even and especially after communities begin to reopen their economies. We hope our projections and analysis will be helpful in that regard.

We will continue to provide updated projections at Please reach out with any questions, we would be happy to assist you.