Alternative Vote: Busting a myth

By Michael Calderbank

Some cynical Labour opponents of reform argue that it would be likely to cost the party across the board in seats where Liberal Democrats are in second place. They argue, quite illegitimately, that the preferences of Conservative voters would transfer en masse to the Lib Dems, and thus cost Labour seats in which it currently enjoys a decent majority. This is an entirely false hypothetical scenario. Far more likely is that – by passing up the “reform dividend” suggested by the polls – Labour would be jeopardising seats in Lab/Con marginals:

The idea that Conservative preferences would transfer almost unanimously to the Lib Dems to defeat Labour candidates is not born out by studies of transferred preference in real elections. Evidence from other contests in which preferential voting is used implies that around 20% of the Conservative vote would not subsequently transfer on elimination. Another, albeit smaller, minority would transfer to parties to such as UKIP, the English Democrats or the BNP. A small number of preferences are even likely to transfer even directly to Labour as a result of local idiosyncracies.

This implies that only in circumstances of a colossal swing against Labour among voters in the political centre-ground (on a scale without historical precedent) would the party lose significant numbers of seats despite enjoying a majority of first preference votes. In the absence of such a catastrophe, it seems highly unlikely that seats like Newcastle upon Tyne East would fall victim to the Lib Dems.

The very fact that AV would have only been secured as a result of the progressive leadership shown by Labour makes such an outcome even more improbable.

On the other hand – on the basis of modelling evidence – in circumstances where an anti-incumbency effect counted against a ruling Conservative administration, Labour would be very likely to benefit from Lib Dem transfers under AV in large parts of the country.