Telephone Households

A telephone household is one that has some type of telephone service on which members of the household, in theory, can be reached by an external party, assuming they are called at a time they will answer their telephone. By definition, a telephone survey of the public can include only telephone households in its sampling frame.

In the United States, in 2007, approximately 97% of all households had landline (wired) telephone service, cell (wireless) telephone service, or both. The approximately 3% without service at a given point in time—the nontelephone households—are households that may have service a few months of the year but cannot afford it consistently. These households are disproportionately low-income renters, who live in very rural areas or inner-city poverty areas. Telephone surveys cannot reach (cover) households without any telephone service, and if the topic of the survey is correlated with whether or not a household has telephone service, the telephone survey may suffer from nonnegligible coverage error.

It was not until the 1970s in the United States that telephone service existed in at least 90% of households, although at that time in certain regions of the country less than 80% of households had telephone service. Nowadays the vast majority of households in the United States have both landline and cell telephone service, although reliable and up-to-date statistics on the exact proportions of landline only, cell phone only, and those that have both types of telephone service are not routinely available, especially not at the nonnational level. However, as of late 2007, a federal government study determined that 20% of U.S. households had only cell phone service and approximately 77% had landline service (with most of these also having a cell phone). Survey researchers who choose to sample the public via telephone must pay close attention to the prevalence of telephone households in the geographic areas that are to be sampled. Many challenges exist for telephone survey researchers as of 2008 due in part to (a) the rapid growth of the cell phone only phenomenon, especially among certain demographic segments of the population (e.g., renters and adults under the age of 30), (b) number portability, (c) difficulties in knowing how to properly sample from both the landline and cell frame, especially at the state and local level, and (d) difficulties in knowing how to weight the resulting data that come from both frames.