Downsian economic theories of democracy which see voting and party positioning as akin to a market are completely inapplicable to the Lib Dems. Rather than moving to the centre, as the model predicts, they’ve enjoyed much more success since abandoning the tactic of “equidistance� after the 1992 election, and staking out their own territory.

Downs never claimed to have developed a universal theory of electoral democracy for all times and places. His theory was conditioned for a particular time and place, the West during the “end of ideology” fifties. To the extent that more states resemble this form of life then his theory will be more applicable. There is a strong sense of deja vu between that time and “the end of history” nineties.

The economic theory of democracy predicts that, in two party contested electorates where the ideological preferences function presents a unimodal distribution with little deviancy, there will be a policy convergence between the parties as voters chase the median voter. Tweedle dum and Tweedle dee.

This model fairly well predicts the behaviour of Australia’s party system where the underlying socio-biology of the electorate more or less fits the models assumptions. This was not the case in the pre-war era when the ALP and the LN/P were committed to (ethnic) clan-based (economic) class conflict ie Orange v Green

Australia is now well on the way to “the Great Convergence” of parties since our basal level of class, clan and cult conflict is now fairly low. This is in part due to Howard’s aggressively normalising cultural policies and his own elegant back-flips.

The Left have given up on class war, the Right have won the cult war, we are all so over the civilization clash and we are all Greenies now. So parties are all in a rush to get on the me-too bandwagon.

In the case of the US and UK there is substantial class and cult conflict based on social fragmentation of communities. In the US this has caused a major party cleavage as the Republicans have lurched to the Right of the Dems.

Downs theory does predict median voter convergence where ideological preferences diverge on multi-dimensional issues. In the UK Blair pushed the Labor party to the Right on economics whilst the Lib Dems have listed to the Left on cultural matters. Britain, in short, is a divided community where there is no sensible median.

Whether Downs conservative democratic model returns back to earth depends on how these states handle the problem of reconciling global trend of increasing economic stratification with decreasing ethnic segreation.

Then you’ll have 38,700,000 articles to choose from!

They did discuss scenarios where room was available for third parties on the fringes.

Remember also that Australian parties can stray further from the median to capture more wing votes, because preferences eventually flow to them. You might think of two overlapping curves.

By choosing the Liberal Democrats, you are sending an equivocal signal. Are you voting for them because you think Blair is too right-wing, or because you fear Old Labour might resurface? Are you choosing them because you are a liberal Tory who detests Michael Howard, or is it because you can’t make up your mind, and they represent the middle position? There are, in other words, too many reasons for voting LibDem. Your voice is lost in the noise of conflicting intentions, and your decision becomes unintelligible. Whoever takes power after the next election cannot be sure why the votes fell the way they did.

If, on the other hand, you were to vote Green, Plaid Cymru, Respect or Scottish Socialist, you would send an unequivocal signal about the kind of politics you are rejecting and the kind of politics you are embracing.

He says that:

All four of them are solidly to the left of Labour. They have been consistently anti-war, anti-privatisation, pro-distribution and pro-environment. No one who has read their manifestos can doubt that a vote for one of them is a vote against the current deference to wealth and rank.

And, he claims, a vote for the minor parties will not let the Tories in.

The authors write:

Downsian modelling of public preferences tends to assume that third parties are destined to fight for a limited political space around the ‘centre’ of political opinion.

The point is not that politics moved towards One Nation because of abstract notions, the point is that it forms an example of the abstract theory’s predictions.

“Hyperdimensional” sounds like science fiction. It essentially means “more than three dimensions”, reflecting the fact that there are more than three issues in a given election (surely).

Calling the Keating consensus was probably optimistic, however you must admit that the shape and discourse of politics under Hawke-Keating had some hangover into the early Howard years, until Hanson excused and made permissible commentary on issues of race, immigration etc from perspectives which were generally squished during the Keating years.

Also, you should remember that the median voter is different in each electorate - part of the challenge for parties is to tailor their position for different areas.

But it’s not true to say that this is the only strategy for winning votes. In fact you can see how the model predicts votes for parties closer to the fringes - they are closer to X voters, who will stop with them rather than heading towards the median. However that number will always be smaller.

One finding of the more advanced theory - and I admit I didn’t fully understand the argument - is that there are multiple clusters of median policies in a voter hyperdimensional issues space. Political landscapes can suddenly and very rapidly migrate from one to another: in Australia the sudden blossoming of One Nation is an example which swept away the Keating Consensus.

Their key constituencies appear to be socially liberal. The derided chardonnay or latte left, well educated, inner city, seem to like them. Non-white people who aren’t enamoured with Labour’s socialist and unionist roots would find them an attractive alternative too, given they know how close to the top of the conservative hand lies the race card. I think the seats they’ve picked up may reflect this, but correct me if wrong.

Socially left, economically centrist, perhaps?

I haven’t seen this book, but it seems obvious that it’s only possible for a party to be distinctive without being left nor right, if the issues cut across across two dimensions. It’s true that in this situation the median voter theorem may fail to predict an outcome. But this is because the median voter may not exist. And this is a standard result in the public choice theory: there is a lot of literature on the causes and consequences - poitive and normative - of the phenomenon. It’s hardly fair to suggest that it somehow defies or discredits the ‘economic theory’. There may be lots of things wrong with public choice theory, but overlooking multi-dimensionality in policy options isn’t one of them.

I expect that they might well give Blair’s mob a run for their money in certain seats as well.