This report was made possible by The Pew Charitable Trusts. Pew Research Center is a subsidiary of The Pew Charitable Trusts, its primary funder.
This report is a collaborative effort based on the input and analysis of the following individuals:
Research team
Courtney Kennedy, Vice President, Methods and Innovation
Dana Popky, Associate Panel Manager
Scott Keeter, Senior Survey Advisor
Methodology
Arnold Lau, Research Methodologist
Communications and editorial
Rachel Drian, Associate Director, Communications
Nida Asheer, Communications Manager
Talia Price, Communications Associate
David Kent, Senior Copy Editor
Graphic design and web publishing
Bill Webster, Senior Information Graphics Designer
Sara Atske, Associate Digital Producer
We are grateful to the many colleagues across the field who responded to our request to confirm or correct information we had gathered about their national public polling. Several individuals went above and beyond, offering insights about why various changes occurred. We appreciate everyone who took the time to respond. Within Pew Research Center, we thank Carroll Doherty and Claudia Deane for providing useful feedback on a draft of the report.
We are also grateful to organizations that maintain databases of public polls, which facilitated some of the data collection for this study. These include the Roper iPoll, the Inter-university Consortium for Political and Social Research, the Louis Harris Data Center operated by the University of North Carolina Odom Institute, and FiveThirtyEight.com.
