%D 2020 %N w26954 %T U.S. Economic Activity during the Early Weeks of the SARS-Cov-2 Outbreak %A Daniel Lewis %A Karel Mertens %A James H Stock %O This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. %C Rochester, NY, USA %X This paper describes a weekly economic index (WEI) developed to track the rapid economic developments associated with the response to the novel Coronavirus in the United States. The WEI index shows a strong and sudden decline in economic activity starting in the week ending March 21, 2020. In the most recent week ending March 28, the WEI indicates economic activity has fallen further to -6.19% scaled to 4 quarter growth in GDP. %L discovery10160494 %S NBER Working Paper w26954 %I SSRN