The Marketplace-Edison Research Poll is a national survey of Americans ages 18 years and older. A total of 1,016 respondents were interviewed with 501 interviews conducted by telephone and 515 interviews conducted online. Among the telephone interviews, 300 were conducted via a landline phone and 201 interviews conducted via a mobile phone so that the proper proportion of coverage of households in the United States that do not have a landline phone would be achieved.
The landline and cell phone sample of phone numbers and the email addresses for the online survey were provided by Survey Sampling International (SSI). The average length of the telephone interviews was sixteen minutes. The interviews were conducted from September 8-18, 2015. The data was weighted to match the most recent United States population estimates from the U.S. Census Bureau for age, gender, race and region of the country. With a total sample size of 1,016 respondents, the calculated margin of error with a 95% confidence interval for results among the entire sample is +/- 3%. The calculated margins of error for results among smaller sub-groups are higher.