How the first time incumbency bonus can impact on the uniform national swing seat projections

July 27th, 2013

Labour incumbents also did better at GE2010

The Tories will have many more first time incumbents

The charts above are based on data from a post-2010 paper by Prof John Curtice, Dr Stephen Fisher and Dr Rob Ford, and looks at the impact of incumbency at the 2010 general election.

As can be seen the type of CON seat where the party did least well were in seats they were trying to retain but with a new candidate. Next up are those seats where incumbents were standing and the third column shows how first-time incumbents standing again fared.

The difference is quite marked ranging from 2.9% where a new candidate stood in a CON seat to 5.9% in those seats which had been won in 2005 and which the incumbent was defending for the first time.

One of the drivers of the first time incumbency bonus is that new MPs build up the party organisation in their constituencies as well as developing a bigger local profile through surgeries, case-work and the like. The overall impact is that they achieve bigger swings compared with candidates for their party standing for the first time or those seeking a second or subsequent re-election.

    If that happens at GE2015 then it could help the Tories in the marginals they are trying to defend.

What will be very interesting will be what happens where Labour re-select the former MP who was defeated last time. Will that reduce the impact of first incumbency?

Mike Smithson

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