Renter protection policies that have curbed mass evictions during the COVID-19 pandemic have played a key role in preventing the spread of SARS-CoV-2 in U.S. cities, according to a new study published in Nature Communications.

Using an epidemiological model to predict how evictions and eviction moratoria would impact the epidemic, the researchers found, for instance, that in a city of 1 million in which 1% of households experience eviction monthly, the evictions could lead to up to 49,000 excess COVID-19 infections. In Philadelphia alone, a fivefold increase in evictions, predicted by some economic analyses, could lead to 53,000 extra infections. The study was led by researchers at the Perelman School of Medicine at the University of Pennsylvania, Johns Hopkins University, and the University of Illinois at Urbana-Champaign.

“Our model shows clearly that policies to stem evictions are not only a warranted but a necessary component of COVID control. As long as the virus is circulating, ending these protections could have devastating implications in the United States,” said co-senior author Michael Z. Levy, an associate professor of epidemiology in Penn’s Perelman School of Medicine.

Record levels of unemployment have put millions of Americans at risk of losing their homes throughout 2020 and 2021. At the start of the pandemic, many cities and states enacted temporary legislation banning evictions, some of which has since expired. On September 4, 2020, the Centers for Disease Control and Prevention (CDC) imposed a national moratorium on evictions, which was extended in March 2021. In addition to a number of well-documented adverse outcomes, evictions would also have outsized repercussions on the growth rate of the COVID-19 epidemic, Dr. Levy and his research team predicted in the summer of 2020. The effect emerges from increases in household sizes—data suggest that, once evicted, households tend to “double-up,” moving in with friends or family. Household transmission can also limit or delay the effects of measures like lockdowns, which aim to decrease the contact rate in the general population.

To quantify this effect, the researchers modeled evictions that resulted in the “doubling up” of households by merging each evicted household with one randomly selected household in the network. They then adjusted the number of contacts outside the household over the course of the simulations to capture the effects of lockdown measures and their subsequent relaxation. They found that with a low monthly eviction rate of 0.25%, an estimated 0.5% more of the population could become infected with COVID-19—or about 5,000 excess cases per 1 million residents—compared to if there were no evictions. A 1% monthly eviction rate could lead to 19,000 to 49,000 excess cases. With an eviction rate of 2% per month, that number jumps to 50,000 to 100,000 excess infections in a single city.

“Our results suggest that the CDC-mandated national order prohibiting evictions from September 4-December 31, 2020 likely prevented thousands of excess COVID-19 infections for every million metropolitan residents,” said the study authors.

The research team therefore adjusted their model to evaluate the effect of evictions in Philadelphia, which has one of the highest eviction rates among large U.S. cities. In July 2020, Philadelphia’s City Council passed the Emergency Housing Protection Act in an effort to prevent evictions during the pandemic. The city was sued by a lobbyist group, which questioned whether the legislation was of broad societal interest, rather than protecting a narrow class of residents. This prompted Dr. Levy’s team to assess the claim.

Their simulations showed that allowing evictions to resume in Philadelphia could substantially increase the number of COVID-19 infections in the city, and that these increases would be felt among various socioeconomic populations, including those experiencing a low number of evictions. With evictions occurring at only their pre-pandemic rates, the epidemic would infect an extra 0.3% of the Philadelphia population, or 4,700 individuals. However, the researchers point out, many economic analyses predict the eviction crisis could be much higher if allowed to resume, due to the economic fallout associated with COVID-19. With a five-fold increase in evictions, excess infections would increase by 53,000 in the city.

Adapted from a Penn Medicine news release. Read the full story here.