# A Queensland state election predictor using the 2016 Senate results as a basis
Date: 2017-10-07

Projections

Predictor •

Analysis

Following on from previous work projecting the 2016 Senate results onto
the new Queensland state seats, I thought I might try a non-uniform
swing model.

This model predicts the primary votes in each seat D_p (or in this case,
four-party-preferreds, which given the number of parties in Queensland
amounts to almost the same thing) from:

- The primary vote for the party statewide at the last election S_e
- The primary vote for the party in that seat at the last election D_e
- The primary vote for the party statewide from a poll of your choice
  S_p

This is done by means of monotonic cubic spline interpolation, between
the points (0, 0); (S_e, D_e); (1, 1).

Such an interpolation makes a great many simplifying assumptions about
the relationship between the statewide primary vote for a party and the
vote it will get in a seat, and I’m not claiming any serious predictive
power!

Something I do which is comparatively novel in the Australian
psephological space is the Senate-votes 4PP - although admittedly
nobody’s really had the opportunity to do one of those until last year!

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Let’s examine the model in more detail. Using the 4PPs we get a
base-case for each district. We perform an interpolation for each
district, and then evaluate the district primary votes D_p for each
party with their new expected statewide primary vote.

From there, we can simulate an election, performing eliminations and
distributing preferences in line with what we know from 2016.

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Enter predicted four-party-preferreds as percentages:

Percentages

Greens:

Labor:

Liberal National:

One Nation:

Seat Tally

Two Party Preferred

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Be aware also of seat-specific stuff - for example, [One Nation isn't
standing candidates against some sitting
MPs.](https://www.brisbanetimes.com.au/politics/queensland/election-candidates-to-be-finalised-within-weeks-as-speculation-mounts-20171009-p4ywdc.html)