Wireless Nation

From CDC:

The second 6 months of 2016 was the first time that a majority of American homes had only wireless telephones. Preliminary results from the July–December 2016 National Health InterviewSurvey (NHIS) indicate that 50.8% of American homes did not have a landline telephone but did have at least one wireless telephone (also known as cellular telephones, cell phones, or mobile phones)—an increase of 2.5 percentage points since the second 6 months of 2015. More than 70% of all adults aged 25-34 and of adults renting their homes were living in wireless-only households. This report presents the most up-to-date estimates available from the federal government concerning the size and characteristics of this population.

This trend creates challenges for public opinion research. 

Many health surveys, political polls, and other types of research are conducted using random-digit-dial (RDD) telephone surveys. Despite operational challenges, most major survey research organizations include wireless telephone numbers when conducting RDD surveys. If they did not, the exclusion of households with only wireless telephones (along with the small proportion of households that have no telephone service) could bias results. This bias—known as coverage bias—could exist if there are differences between
persons with and without landline telephones for the substantive variables of interest