This is a technical piece about the meaning of a type of polling. It is not political in favor of or against President Trump. I will remove any political comments.
What are presidential approval polls?
Presidential approval polls are a simple concept to grasp: do you approve or disapprove of President X? Because newspapers and TV channels can always use them for a headline or an on air-segment, they love to commission them. During President Trump's presidency, I counted 16,500 published approval polls.
But what do these polls mean and how should we interpret them? As it turns out, understanding what they're telling us is slippery. I'm going to offer you my guide for understanding what they mean.
My data comes from the ever-wonderful 538 which has a page showing the approval ratings for President Trump. Not only can you download the data from the page, you can also compare President Trump's approval ratings with many previous presidents' approval ratings.
Example approval results
On 2020-10-29, Fox News ran an approval poll for President Trump. Of the 1,246 people surveyed:
- 46% approved of President Trump
- 54% disapproved of President Trump
- 51% approved of President Trump
- 48% disapproved of President Trump.
- Gravis Marketing, 1,281 respondents, 52% approve, 47% disapprove
- Morning Consult, 31,920 respondents, 42% approve, 53% disapprove
Plotting approval and disapproval over time
- 2020-10-25, approval 42 ± 2.6%, disapproval 56 ± 2.6%, undecided 2 ± 0.7%
- 2020-10-26, approval 42 ± 2.6%, disapproval 56 ± 2.6%, undecided 2 ± 0.7%
- 2020-10-27, approval 42 ± 2.6%, disapproval 56 ± 2.6%, undecided 2 ± 0.7%
Variation between pollsters
How might you run an approval poll?
There are two types of approval polls.
- One-off polls. You select your sample of subjects and ask them your questions. You only do it once.
- Tracking polls. Technically, this is also called a longitudinal study. You select your population sample and ask them questions. You then ask the same group the same questions at a later date. The idea is, you can see how opinions change over time using the same group.
How accurate are approval polls?
What about averaging?
- Do you include tracking polls or all polls?
- Do you weight polls by their size?
- Do you weight polls by accuracy or partisan bias?
- Do you remove 'don't knows'?
- If a poll took place over more than one day, do you average results over each day the poll took place?
What all this means
What can I conclude for President Trump's approval rating?
What about President Biden?
If you liked this post, you might like these ones
- Forecasting the 2020 election: a retrospective
- What do presidential approval polls really tell us?
- Fundamentally wrong? Using economic data as an election predictor - why I distrust forecasting models built on economic and other data
- Can you believe the polls? - fake polls, leading questions, and other sins of opinion polling.
- President Hilary Clinton: what the polls got wrong in 2016 and why they got it wrong - why the polls said Clinton would win and why Trump did.
- Poll-axed: disastrously wrong opinion polls - a brief romp through some disastrously wrong opinion poll results.
- Who will win the election? Election victory probabilities from opinion polls
- Sampling the goods: how opinion polls are made - my experiences working for an opinion polling company as a street interviewer.
- The electoral college for beginners - how the electoral college works