A new study by Columbia University Mailman School of Public Health researchers poses a hypothetical question: What if air quality improvements in New York City during the spring 2020 COVID-19 shutdown were sustained for five years without the economic and health costs of the pandemic? They estimate cumulative benefits of clean air during this period would amount to thousands of avoided cases of illness and death in children and adults, as well as associated economic benefits between $32 to $77 billion. The study's findings are published in the journal Environmental Research.