How will the introduction of probability sampling affect the CES program?
The CES program is not only converting to NAICS, but has also been switching from a quota-based sample to a probability-based sample for preparing monthly employment estimates. Starting in March 2001 with the wholesale trade sector, this change in sampling technique was phased in over a two-year period. Currently, all industry sectors are estimated with probability samples, which offer several key statistical advantages: • Less biased estimates – Quota samples are now known to be at-risk for potentially significant biases, which may lead to an unrepresentative sample. Through random sample selection and improved estimation methodology, a probability-based sample more effectively ensures that estimates will properly represent the universe. • More representation for new firms – Quota samples lack a timely sample-based representation of employment from new business openings. Under probability sampling, a new approach called the net birth/death model has been developed for regular sample u
