Listed Number

A listed telephone number is one that can be retrieved from a telephone company's directory assistance service, and it also may be published in a local telephone directory. The majority of U.S. residential landline (wired) telephone numbers are listed, but a growing proportion are unlisted—more than 40% as of 2008. There is no equivalent concept of “listing” that applies to cell phone (wireless) numbers in the United States, as there are no directory assistance services or telephone directories that are publicly accessible that contain cell phone numbers.

Whether or not a landline telephone number is listed is predictive of the likelihood that a completed interview will be attained with that household in a telephone survey. A greater proportion of interviews are completed with numbers that are ...