The U.S Bureau of Labor Statistics (BLS) (citation, USDL-20-0521) wrote:
March data from the establishment and household surveys broadly reflect some of the early effects of the coronavirus (COVID-19) pandemic on the labor market. We cannot precisely quantify the effects of the pandemic on the job market in March. However, it is clear that the decrease in employment and hours and the increase in unemployment can be ascribed to effects of the illness and efforts to contain the virus. It is important to keep in mind that the March survey reference periods for both surveys predated many coronavirus-related business and school closures in the second half of the month.
In the household survey, individuals are classified as employed, unemployed, or not in the labor force based on their answers to a series of questions about their activities during the survey reference week (March 8th through March 14th). Workers who indicate they were not working during the entire survey reference week and expect to be recalled to their jobs should be classified as unemployed on temporary layoff.
In March 2020, there was an extremely large increase in the number of persons classified as unemployed on temporary layoff. However, there was also a large increase in the number of workers who were classified as employed but absent from work. Special instructions sent to household survey interviewers just before data collection started for March called for all employed persons absent from work due to coronavirus-related business closures to be classified as unemployed on temporary layoff. However, it is apparent that not all such workers were so classified. Such a misclassification is an example of nonsampling error and can occur when respondents misunderstand questions or interviewers record answers incorrectly.
If the workers who were recorded as employed but absent from work due to “other reasons” (over and above the number absent for other reasons in a typical March) had been classified as unemployed on temporary layoff, the overall unemployment rate would have been almost 1 percentage point higher than reported. However, according to usual practice, the data from the household survey are accepted as recorded. To maintain data integrity, no ad hoc actions are taken to reclassify survey responses.
In the establishment survey, workers who are paid by their employer for all or any part of the pay period including the 12th of the month are counted as employed, even if they were not actually at their jobs. Workers who are temporarily or permanently absent from their jobs, but are not being paid, are not counted as employed, even if they are continuing to receive benefits. The length of the reference period does vary across the respondents in the establishment survey; one-third of respondents have a weekly pay period, slightly over 40 percent a bi-weekly, about 20 percent semi-monthly, and a small amount monthly.
Data collection for both surveys was affected by the coronavirus. The household survey is generally collected through in-person and telephone interviews, but personal interviews were suspended during the collection period for the safety of interviewers and respondents. The household survey response rate, at 73 percent, was about 10 percentage points lower than in recent months. In the establishment survey, about one-fifth of the data is generally collected by telephone at four regional data collection centers. Although these centers were closed during the collection period, efforts were made to collect data electronically. The collection rate for the establishment survey, at 66 percent, was about 9 percentage points lower than average.
More information is available at www.bls.gov/cps/employment-situation-covid19-faq-march-2020.pdf
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