UPDATED Mar. 13, 2023, at 3:53 PM

FiveThirtyEight’s Pollster Ratings

Based on the historical accuracy and methodology of each polling organization’s polls.

B/C

University of Southern California Center for Economic and Social Research

Polls analyzed	10
Races called correctly	80%
Most recent cycle	2020
Affiliated with AAPOR/Roper	Yes
Other names

What are pollster ratings?

How accurate are the polls from University of Southern California Center for Economic and Social Research?

Polls conducted within 21 days of an election (based on the poll’s median date) are used to determine the pollster’s grade.

2020

Key

A = Adults

RV = Registered voters

V = Voters

LV = Likely voters

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 20-Nov 2	5,413LV	House (National) General election	Online	Poll Democrats +8.0	Actual Democrats +3.0	Difference 5.0
Oct 20-Nov 2	5,423LV	President (National) General election	Online	Poll Biden +12.2	Actual Biden +4.5	Difference 7.7
Oct 20-Nov 2	5,423LV	President (National) General election	Online	Poll Biden +10.9	Actual Biden +4.5	Difference 6.4
Oct 6-19	5,483LV	House (National) General election	Online	Poll Democrats +7.7	Actual Democrats +3.0	Difference 4.6
Oct 6-19	5,488LV	President (National) General election	Online	Poll Biden +11.6	Actual Biden +4.5	Difference 7.2
Oct 6-19	5,488LV	President (National) General election	Online	Poll Biden +13.1	Actual Biden +4.5	Difference 8.6

2018

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Oct 28-Nov 3	2,521LV	House (National) General election	Online	Poll Democrats +15.0	Actual Democrats +8.7	Difference 6.3
Oct 21-27	2,350LV	House (National) General election	Online	Poll Democrats +17.0	Actual Democrats +8.7	Difference 8.3
Oct 14-20	2,284LV	House (National) General election	Online	Poll Democrats +13.0	Actual Democrats +8.7	Difference 4.3

2016

Dates	Sample	Race	Methodology	Poll margin	Election margin	Difference
Nov 1-7	2,972LV	President (National) General election	Online	Poll Trump +3.2	Actual Clinton +2.1	Difference 5.3
Oct 25-31	3,145LV	President (National) General election	Online	Poll Trump +3.6	Actual Clinton +2.1	Difference 5.7
Oct 18-24	3,104LV	President (National) General election	Online	Poll Clinton +0.9	Actual Clinton +2.1	Difference 1.2

How this works

FiveThirtyEight’s pollster ratings are calculated by analyzing the historical accuracy of each polling organization’s polls along with its methodology. Accuracy scores are adjusted for the type of election polled, the poll’s sample size, the performance of other polls surveying the same race and other factors. We also calculate measures of statistical bias in the polls. When a pollster publishes multiple versions of the same survey (for example, versions with and without third-party candidates included), FiveThirtyEight uses an average of the different versions to calculate the pollster’s rating. However, all versions of these polls are listed here. Read more about our methodology»

Download this data as an Excel spreadsheet or get it on GitHub.

Design and development by Elena Mejía and Aaron Bycoffe. Research by Mary Radcliffe, Cooper Burton and Dhrumil Mehta. Copy editing by Andrew Mangan. Visual editing by Christopher Groskopf. Statistical model by Nate Silver.

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