2018 Governor · IA
Selzer & Co. · fieldwork ended 2018-11-01 (5 days before the election) · 801 respondents · Live Phone
The poll said
Democrat 46% · Republican 44%
D+2.0
The certified result
Democrat 47.53% · Republican 50.26%
R+2.7
The arithmetic
- Poll margin = 46 − 44 = 2.00
- Actual margin = 47.527 − 50.260 = -2.733
- Signed miss = 2.00 − (-2.733) = 4.733
- Absolute miss = |4.733| = 4.733
The poll overstated the Democrat by 4.7 points and had the wrong leader.
Where these numbers come from
Poll and result: 538 raw_polls.csv. Poll ID 56722, race ID 143 (538 database).