2013 House · SC-1
ccAdvertising · fieldwork ended 2013-04-30 (7 days before the election) · 1,807 respondents · IVR
The poll said
Democrat 40% · Republican 39.5%
D+0.5
The certified result
Democrat 41.87% · Republican 54.03%
R+12.2
The arithmetic
- Poll margin = 40 − 39.5 = 0.50
- Actual margin = 41.874 − 54.026 = -12.152
- Signed miss = 0.50 − (-12.152) = 12.652
- Absolute miss = |12.652| = 12.652
The poll overstated the Democrat by 12.7 points and had the wrong leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 73676, race ID 1782 (538 database).