Social distancing should stick around

As the COVID-19 pandemic enters its second year, the worst of it could be behind us, but in order to get comfortable with this notion, Americans may also need to get used to some of the vestiges of the past year’s mitigation efforts. The latest development — a positive one — is that all adults in the U.S. are now eligible for the COVID-19 vaccine. 

Still, with every step forward a new set of questions arises, particularly those centered on the now-famous mitigation efforts of social distancing and mask-wearing. How did we get here? Were the lockdowns effective? How do we keep moving forward the right way? And do we really need to continue social distancing even after we are vaccinated?

We answer part of that last question from some newly-conducted research. It is a resounding, “yes.”

Based on representative COVID-19 data from Minnesota, which I helped gather, social distancing policies are more effective than lockdown policies. In addition, social distancing policies are even more important in the post-pandemic peak period than in the actual peak period. 

Why? Because there is a larger deviation between individual activity levels and socially optimal activity levels. Socially optimal activity level is the activity level that a social planner would like to enforce on each individual, aiming to maximize the total welfare of everyone. It serves as a benchmark. (We know that in practice, a social planner cannot decide an individual’s activity level directly. However, social distancing and lockdown policies could be implemented to influence an individual’s behavior.) 

In other words, when each individual decides whether to go out on a certain day, they would consider the utility of going out and the potential risk of being infected. However, one could easily ignore the fact that once being infected, it also increases the risk of infecting others, which is the negative externality imposed on others. A social planner who wants to maximize the total welfare of everyone will take this into account. Therefore, individual activity level is higher than the socially optimal level. The gap between the two changes in disease prevalence (number of people infected). In our research, we found the gap is small when we are in the peak pandemic period because people are already cautious. The gap is the largest when the disease prevalence is moderate (post-peak pandemic period), which is the time that social distancing should be instituted.

This new research is featured in a paper that is under peer review for publication in the INFORMS journal Management Science, where I am a member. Through our research, we closely studied public policy interventions while also taking into account both the disease burden caused by COVID-19 and the financial loss caused by the disruption to regular economic and social activities. 

We found that lawmakers’ and health leaders’ efforts to continue emphasizing social distancing are most valuable in the post-pandemic peak period, and even now during the period of continuous vaccine rollout. Until herd immunity is achieved, policies to continue social distancing remain the most responsible and reliable mitigation efforts available to everyone.

Our research also looked at the vaccination strategies that centered on focusing on older generations and the most vulnerable first. While vaccinating the elderly population first could reduce the death rate, it could also lead to a higher number of infections throughout society. Although prioritizing the more active general population of adults early could reduce the spread at a larger scale, it becomes a more costly strategy for the society when the disease becomes infectious. Either way, social distancing is still required to mitigate the spread until herd immunity is achieved.

Multiple important factors that we had to consider in this research included how the performance of vaccine strategies is impacted by vaccine production capacity, infection rates and mortality ratios between the adult group and the elderly group. We also had to take into account the presence of more infectious variants, such as those first detected in the United Kingdom and South Africa.

Even against this multifaceted backdrop, we still found that social distancing policies are critical and should be enforced in parallel with vaccine administration to contain disease transmission.

If the United States continues down the same path of current vaccination distribution strategies, broad social distancing policies remain essential to continue to limit a spike in infection rates. Ironically, if you want to put the pandemic behind us and enjoy days without social distancing and mask-wearing, the most effective way to get there and beat the virus that has brought much of the world to a standstill is to adhere to the discipline of social distancing now.

Dr. Guangwen Kong is an assistant professor at Temple University in the Fox School of Business. She holds a Ph.D. in operations management from the Marshall School of Business, University of Southern California. She is a member of INFORMS, the Institute for Operations Research and the Management Sciences.