Monitoring individual political defections gives us a view of which way the political wind is blowing.
Historically more MPs defect for better career prospects, than over policy. On average, defection is a career-enhancing move, with defectors more likely than loyalists to be given ministerial office or a peerage.
With the current state of the parties, the prospects for ministerial office after the next election are unusually equally spread among the parties. There is no obviously sinking ship and no obvious favourite to win the next election, unlike the situation in 1997, 2001 and 2005. Another coalition is a distinct possibility (estimated by David Butler to be a least 50% likely). It would be a gamble for any ambitious MP to jump ship in the hope of landing in another party, where the prospects for office could confidently be predicted to be better. So far, there have been no defections of MPs during this parliament and the uncertainties for the future are likely to keep a dampener on defections for ambitions’ sake, until after the next election
Some MPs do defect over policy disagreements. This is rarer and also, on average, less satisfactory for the defector in the long run. Some Conservative MPs might be tempted to jump ship to Ukip, but it would be a huge leap in the dark to join a party with no MPs, at a time when the policies of all the parties, particularly over Europe, are still fluid.
Rarer still are defections as a result of personality clashes – only accounting for about 3% of defections. There are clashes within every party, but most MPs do not leave because of them.
Therefore, the likelihood of defections of MPs well before the next election is unusually small at the moment. However, election years do tend to produce spikes in defections, so 2015 could turn out to be a bumper year for defections. There is the prospect of a retiring MP making a protest resignation, just before the election, as Brian Sedgemore did in 2005, by defecting from Labour to the Lib Dems. In the current parliament a retiring Conservative, with nothing to lose, defecting to Ukip is a possibility.
Even without an ebb and flow of defecting MPs, we do still have other straws in the wind, to see the prevailing trend in the political climate. Local councillors are more numerous than MPs, are usually outside the glare of the media spotlight and may well be used to working across party boundaries in local council coalitions. Councillor defections happen almost weekly.
The prevailing trend immediately after the formation of the 2010 coalition was for an outflow of councillors from the LibDems to Labour. This drift has now pretty much stopped and recently there have been a few defections of councillors to the LibDems. The dominant trend in councillor defections at the moment is from the Conservatives to Ukip, a pattern which has been established for well over a year.
Are these defections local storms of protest, or signs of political climate change? If you don’t believe in atmospheric climate change, you probably won’t want to believe in my methods for measuring political climate change - but then again, you just might, if the wind is blowing in your direction.