John Quiggin “proposes a test(link to Ideas and Interests on JQs site)”:http://www.johnquiggin.com/archives/001573.html for distinguishing whether a public-interest or private-interest theory of government is more plausible. bq. If ideas about the desirability of policy are adjusted in response toevidence (cf Keynes — when the facts change, I change my mind. What do you do?) then the public interest theory will be valid in the long run. If changes in ideas are determined by the rise and fall of dominant interest groups (as in many Marxist models, and in Schumpeter) private interest theories will be valid in the long run, even though people may believe themselves to be acting in the public interest My own experience tells me that the hardest-fought decisions made at a political level are distributive decisions in which ideas of a sort play a role. But they are ideas that are not particularly sensitive to evidence. I’m skeptical that they sustain a case for a (predominantly) ‘public interest’ theory of government. It would be good to be certain that ideas that inform policy change in response to evidence. But over and over in different domains we see that ideas—as frameworks for understanding the world—change slowly and only in a fashion-driven or maybe crisis-driven way in response to evidence that is frequently ignored or derided for a long period and, only in retrospect, eventually comes to be considered definitive. This is the common experience of much scientific advance: how long did it take for the evidence of bacterial vectors of disease to become ‘evidence’ (about a century), or for the elliptical paths of the planets to be preferred over the impossible epicycloid fantasies of Copernicus (even longer)? The tendency for ‘evidence’ to be invisible until the ‘chicken’ of a new theoretic framework makes it out to be an egg is probably clearest in security intelligence discoveries: how long did it take for the open and repeated evidence of the malignity of Bin Laden’s cells to be even visible to the US or UK intelligence services more concerned with other threats and more comfortable with other explanations? The disinterest of opinion in evidence that requires a revision of important ideas/theories can be seen, positively, of course, as a sort of necessary filter mechanism: saving us from the burdens of continual revision of shared frameworks of understanding and dialogue. We’d be trapped in indecision if we had to break off to chase every odd evidentiary rabbit down it’s theoretical burrow. But whether justified by this practical consideration or not, the inertia of most public policy frameworks makes me very skeptical about the impact of intellectual ideas on policies. I think its much more likely that most of the Ideas (with a capital ‘I’)we say are influential (such as, for example, feminism, federalism, sustainability) are just temporary, local directions: fashionable, intriguing for a while and colourable. But not fundamental. Why don’t young adults stop smoking now that they know the danger and the government makes it graphically clear to them? I suspect that the reasons are obvious to all of us: the intellectual evidence of health risk is trumped by a bigger and more motivational idea. The ideas that have a big and sustained impact on policy are those that motivate people to vote (where it is optional) or donate to causes, go to war or endanger their health by risky behavior. G.K. Chesterton (I am reluctant to acknowledge) correctly noted that the ideas that really have a sustained impact are those that are adequately represented by a nearly empty symbol like a flag: they are atavistic ideas like equity, fraternity, liberty etc. It’s arguable, I think, that it’s something like the idea of liberty that trumps the horror-advertising about smoking. Sometimes these motivating ideas wear the appearance of a fashionable idea: how much of the attraction of feminism is a powerful appeal to ‘fair play’? They don’t turn up overtly in policy debates all that often, thank god, or we’d probably be at war more often than we are. But they erupt sometimes in the strangest contexts: I suspect that despite the often noted frequency of divorce, the idea of (heterosexual) marriage is one such an atavist idea in the USA (and maybe in Australia) whose defense is inevitable and will not provide anyone with a distinguishable campaign platform. What fills the interstices between eruptions of genuinely motivating ideas into political debate? In my view: private interest. That’s what I and many other ‘public-policy advocates” do for a living: we position a private interest in the spectrum of current exchanges that are filled with received ideas about policy. What the French call ‘le discours’. We argue for funding for infrastructure projects on the basis of respect for the principles of federalism or the elimination of trade barriers on the basis of economic efficiency etc. etc. But these ideas frequently seem to me to be less important for their content than for their role as gestures: they help to define clients, form alliances. It’s a discourse of the elites, of course. You can’t justify a freeway to the punters on the basis of town-planning (it has to be something like ‘equity’). But the consensus of different elites—however driven at the margin by the latest fashionable idea—is the battleground over which most short-run distributive contests are fought. All this, too, will pass. When Keynes said that in the long-run we’re all dead, he only meant you and me. None of us believes that the world will end when we do: each of us hopes, somehow, that he or she will make a difference in the long-run even after we’re dead. That’s the sort of much bigger idea that motivates all of us and, in the long-run, is the most politically effective.