Yet another, but not altogether serious, statistic about elections which is easily captured is the age difference between the contenders (Prime Minister and Leader of the Opposition), shown for the post-war period in the chart below.
The green shadow indicates where the election generated a change of governing party. 1945, following the wartime coalition led by Winston Churchill, and 2010, leading to a Conservative/Liberal Democrat coalition led by David Cameron, are assumed to be changes of party. Eight of the 20 elections were then of this kind. In the four elections from 1966 to 1974 the age difference between the contenders was insignificant, Harold Wilson being born in March and Edward Heath in July 1916. For this reason, no conclusions can be drawn about the 1970 and February 1974 changes of government. However, in five of the remaining six elections in which there was a change of party, the successful challenger was younger, on four occasions by 10 years or more. The only older successful challenger was in 1951, when, having failed to displace Clement Attlee in 1950, Churchill returned to the Prime Ministership.
In the 12 continuity elections (ie with no consequent change of governing party), Wilson’s successes against Heath in 1966 and October 1974 are as before insignificant as far as age differences are concerned. Cameron’s success in 2015 against Ed Miliband, who was three years younger, and John Major’s in 1992, when a year and a day older than Neil Kinnock, are probably best regarded as inconclusive as well. In the eight remaining continuity elections, three of the victors had an age advantage of more than 10 years and two were more than five years younger. Three were older, Margaret Thatcher’s defeat of Kinnock in 1987, when more than 15 years older, being easier to understand than Harold Macmillan’s of Hugh Gaitskell in 1959 when more than ten years older.
Is there any underlying significance to all this? It could be that for the electorate to move a party from opposition to government, there has to be an appetite for change and the case for fulfilling it can be made more convincingly by a younger person – Wilson in 1964, Margaret Thatcher in 1979, Tony Blair in 1997, Cameron in 2010.
And what should the two parties’ strategies be for the next election if they were to take age advantage seriously? Labour would, it seems, be more likely to succeed in selling change to the electorate with a much younger leader than Jeremy Corbyn, 68 but now not easily dislodged. It is worth noting that while Cameron at 43 in 2010 was the youngest PM since 1812, Justin Trudeau became Canadian Prime Minister in 2015 at the same age and Emmanuel Macron was elected president of France this year at 39. Labour might well want to wait for the Tories to move first but ought already to be considering that their man or woman should be much more than five years younger than Boris Johnson or Amber Rudd (both currently 53) and significantly younger than Michael Gove (49, going on 60) or Sajid David (47). The Conservatives (on the assumption that Theresa May is no longer PM by then) should aim to nullify any future Labour leader’s age advantage by choosing someone in their early forties. It would also be to the Tory’s advantage to play it long and keep Labour waiting. Oh, and if they'd been to Oxford ...
Anyone thinking of starting up a new party under, say, David Miliband, should remember that he is 52 next month. How time passes.
Update 27 June 2017
On 25 June, the Sunday Telegraph carried an article by Ben Riley-Smith, Tory plot to skip 'toxic' generation and install younger face as next leader.
Tory MPs and donors are plotting to “skip a generation” and install a younger MP as their next leader after concluding the front-runners to replace Theresa May are too toxic. A growing number of Conservatives believe that Boris Johnson and David Davis have “had their day” and only younger faces can revive the party’s fortunes.
… Hopes are now turning to the “golden generation” of Tory MPs first elected in 2010 to win back younger voters who voted for Jeremy Corbyn en masse at the election. Sajid Javid, the Business Secretary, Dominic Raab, the Eurosceptic justice minister, and Priti Patel, the International Development Secretary, are all being talked up by colleagues. Other ministers from the 2010 intake such as Jesse Norman, Brandon Lewis and Jo Johnson - the brother of Boris - are also mentioned as possible contenders.
Supporters of the plan point to how David Cameron, the last Tory to win the party a majority, was barely known when he joined the leadership race in 2005.
“If and when this happens, we need Year Zero – a real radical revolution,” said one 2010 MP about a leadership switch. “We need an equivalent to Ruth Davidson [the Scottish Tory leader] – someone completely counter-intuitive. She is a lesbian kick-boxer who doesn’t fit the mould. When she first got elected she didn’t have much cut through. But because they are new and different it will gather stream [sic].”
One veteran MP warned that “all the front-runners are contaminated in one way or the other". Another younger MP said: “They’ve had their day and it hasn’t worked. For the current lot – Boris and the rest of them – their time is up.
Raab is 43; Patel, 45; Norman, 55; Lewis and Jo Johnson, both 46.