The analysis in this report is based on two nationally representative telephone surveys conducted in the United States in 2014 and 2009. For both of the surveys, interviews were conducted in English and Spanish by Princeton Data Source under the direction of Princeton Survey Research Associates International.

The 2014 telephone interviews were conducted Oct. 27-Nov. 24, 2014, among 1,692 adults ages 18 and older living in the 50 states and the District of Columbia (675 respondents were interviewed on a landline telephone, and 1,017 were interviewed on a cellphone, including 568 who had no landline telephone). The margin of sampling error for the complete set of weighted data is plus or minus 2.7 percentage points. For more information on this survey’s design and methodology, see https://www.pewresearch.org/social-trends/2015/05/21/about-the-surveys/

The 2009 telephone interviews were conducted Feb. 23-March 23, 2009, among 2,969 adults, ages 18 and older, living in the continental United States. The margin of sampling error for the complete weighted data is plus or minus 2.6 percentage points. For more information on this survey’s design and methodology, see https://www.pewresearch.org/social-trends/2009/06/29/growing-old-in-america-expectations-vs-reality/#about-the-survey

For more detailed information about our survey methodology, see https://www.pewresearch.org/methodology/u-s-survey-research/

The trend analysis on living arrangements of older adults utilizes the 1990-2000 decennial U.S. censuses and the 2010 and 2014 and the American Community Surveys (ACS) provided by the Integrated Public-Use Microdata Series (IPUMS). The IPUMS assigns uniform codes, to the extent possible, to data collected in the censuses and ACS over the years. Figures for 1900-2000 use the 1% samples, including the 1970 Form 1 metro sample. More information about the IPUMS, including variable definition and sampling error, is available at https://usa.ipums.org/usa/doc.shtml.