Conventional wisdom changes over time.
There are two ways to discuss this, the crude, and the technical.
If you're crude, it's fun to discuss things the technical way; if you're technical, it's fun to discuss it crudely. I'm a a bit crude and a bit technical, so I'll share my thoughts on how convention wisdom changes in both ways.
The crude first.
There are two folks sayings (one is actually a Gandhi quote, but that makes it sound a bit high-falutin', so let's just ignore that weird old sexually hung-up dude and call it a folk saying). Anyway:
Science doesn't advance when minds are changed; it advances when old scientists die.
First they ignore you, then they laugh at you, then they fight you, then you win.
The point being contrary to the nice crisp models of the scientific process, (a) the more data you get to support your side, the more vehement the other side gets, and (b) there's no amount of data that can convince some people. You just have to wait until they get somewhat less attractive, and corpsified, and gross, and then continue the conversation over their age-whithered remains.
Now the technical:
Thomas Kuhn's The Structure of Scientific Revolutions is one of those books that everyone with pretensions to intellectualism should read.
For that matter, so is C.P. Snow's essay "The Two Cultures".
The difference is that I've actually read The Structure of Scientific Revolutions. It's not quite as deep – nor as original – as its reputation suggests, nor could it be. The name of the book has become something of a totem – loaded (not "freighted". I hate that term. Unless there are actual, literal forklifts or cranes involved you can stick your "freighted" right next to your "fraught" in your hipster-pretentious-J-school three ring binder, and shelve it next to Salon.com and the NYT style pages).
Uh…where was I?
Right, right. "The Structure of Scientific Revolutions". "Freighted". "Hipsters".
Anyway, the name of the book is loaded with a lot of cultural signifiers and baggage, because that's what pretentious intellectuals do, and because the book is a convenient stick in the dirt and thus its title is as good a phrase as any to label that patch of ground.
The patch of ground being the social process by which conventional wisdom changes.
Kuhn argues (to simplify) that at any given point in time there is a dominant theory. If the theory is hugely dominant, and there are no observed problems with it, there's little action, and no one much cares.
Had any rousing debates about electron shells, the mass of a neutron, of the photovoltaic effect recently?
Nor have I.
However, from time to time, a theory that was dominant gets some countervailing data piled up against it.
…and then a bit more.
…and then a bit more.
In theory there's no difference between the model of the scientific process and the actual practice of science.
…but in actual practice there is.
In theory academics of whatever stripe – physicists, chemists, economists, political scientists – would welcome contrary opinions and contrary data.
We all know what we really see, though: anger, fear, and outrage.
This is because the theory of the scientific process oversimplifies: it forgets that academics are first and foremost humans, and humans are the end product of a whole butt-load of tribal living.
…and when it comes to tribal living, the powerful get first choice of meat and first choice of nubile hunter-gatherers-of-the-curvy-variety.
Thus we humans can be fairly prickly about power, status, and signaling (you can Google up Tyler Cowen and Robin Hanson on your own). When it comes to power dynamics in the nerd – ah – academic set, there's something a lot worse than being challenged by the first-row, second-seat sax player, or having your rook snatched by the kid with an Elo score one notch down from yours. These challenges will just have you lose one or two ranks. The thing that's a lot worse is being kicked out of the group all together: being made a laughing stock and mocked as utterly, entirely wrong.
And, of course, this is exactly what the scientific process – as it's SUPPOSED to work – threatens to do to non-ideal actual-human-meat academics.
So the Old Guard fight as hard and as long as possible…and they get more and more angry as the evidence piles up against them.
…and eventually the expire and the old much-hated ideas are allowed to be spoken in public.
Paul Graham touched on this in his essay What you Can't Say:
To launch a taboo, a group has to be poised halfway between weakness and power. A confident group doesn't need taboos to protect it. It's not considered improper to make disparaging remarks about Americans, or the English. And yet a group has to be powerful enough to enforce a taboo.
Anyway, having quoted two bumper stickers, one philosopher of science, and one start-up millionaire (as well as mocking a universally-beloved 20th century saint), I arrive at my point:
After almost 150 years, the idea of the universal welfare state may be crumbling before our eyes.
The welfare state – at least the American version of it – is like a shark that must constantly swim forward or die. It's like an embezzling employee who must not only show up at work every day to cover her tracks, but must steal more and more to cover the old debts plus new expenses. It's like a Ponzi scheme.
In fact, it's not like a Ponzi scheme, it is a Ponzi scheme. Both at a concrete level and at a conceptual meta-level.
The American welfare state must constantly grow because it is as much a social system of outrage, signaling, and demonstrated "compassion" (those damn dirty apes – uh, I mean "humans" – again). If you're a good progressive and you're born into a system that already has emergency health care for the poor, welfare, free schooling for all, etc., etc. ad nauseam, then how do you demonstrate to the 20th century version of the hunter-gatherers-of-the-curvy-variety that you're a good person with all the right opinions and thus deserve a bunch of crazy monkey sex worthy of a Dan Savage column?
You agitate for even more welfare statism.
(I note that I could have merely referenced the hedonic treadmill to explain all of this, but that wouldn't have allowed me to use the phrase "crazy monkey sex", and I bet Ken two free hours of dental-expert-witnessing that I could work that phrase into every single post for the remainder of the year. I won't even tell you what I get if I win.)
And thus we run into the problem we see today: the economic meltdown.
As Margaret Thatcher famously said "the problem with socialism is that eventually you run out of other people's money".
Bush bought an election or two by buying off the votes of elderly with prescription drug benefits.
Obama's been trying to buy himself a second term since Day One buy buying GM from its creditor/owners and handing it to the unions…along with a thousand other equally stupid schemes.
…but the moment of reckoning that many of us have seen since the 1980s has finally arrived.
We've run out of other people's money.
You can see the graphs everywhere in the economic blogosphere: expenditures racing far beyond revenues and never ever ever being caught.
This leads us to the second shoe drop, which is only a few years away: the point where the government is not just spending wildly more than it takes in, but the point where it becomes physically impossible to even keep up with the interest payments on the debt.
And then the – uh – gripping foot drops a third shoe: as the market sees this point coming, it gets more and more leery of lending any more money to the government, thus bidding up the interest that the government must pay in order to borrow additional dollars.
This is basically a tripwire: as soon as the apocalypse can be seen on the horizon we're rapidly accelerated towards it.
So, back to Kuhn and others: this has all been clear to some folks for a quarter century or more, but it's finally becoming more and more clear to the average man in the street.
In a better world the Krugmans and others would say "hmm…this isn't how I expected things to play out; perhaps my theories are wrong".
…but the Krugmans and others are afraid of losing their status and their access to crazy monkey sex (although I think the NYT still pays in dollars and suggests that columnists go procure on their own…although I admit that that may change as the dollar devalues).
Over the last few decades libertarianism / governmental minimalism / the night watchman state has gone from being a term that most folks had never heard of, to being a concept that just a bunch of low status geeks and freaks chatted about in between rolling the d20, to being a virulent / arrogant / hateful / racist concept.
The welfare state is dying, the evidence is becoming more and more clear, the Chief Monkeys are losing their power, and the world is about to undergo the kind of intellectual revolution and tumult that it only sees once every few centuries or so.
Punctuated equilibrium – it's not just for meatspace evolution any more.
P.S. Hi. I'm Clark. Nice to meet y'all.