Against evidence-based policy

What is the case against evidence-based policy? This is one question prompted by David Cameron's refusal to legalize drugs in the face of evidence that criminalization of them doesn't reduce their use.

The question, of course, generalizes. Many of us would argue that fiscal policy and immigration policy are also less than perfectly based in the evidence - and no doubt you can think of other examples. There must, therefore, be something to be said against evidence-based policy. But what?

One answer lies in something we know from financial decision-making - that greater knowledge doesn't necessarily improve the quality of decision-making. It might instead merely increase people's overconfidence and so magnify their mistakes.

This matters because in a complex world there is inevitably a lot that cannot be known about effects of policy, particularly in the long-run and about the possible effects of policy upon social norms. For example, whilst there is good evidence that immigration doesn't reduce wages on average, and might even increase them, there is - as Diane says - rather less hard evidence about their long run effects. Might it be that, in the long-run, a more ethnically heterogenous society would lead to greater tolerance of inequality? Or take tax policy. There might (pdf) be some evidence that higher taxes on top earners would, in the short run, raise revenue. But what about the possibility, stressed by Assar Lindbeck, that redistribution might in the long-run erode social norms in favour of work?

There's a lot that cannot be known about policy effects. Stressing the need for evidence might therefore cause us to overweight partial knowledge and so lead us astray.

I'd add three other arguments:

 - Evidence-based policy is, necessarily, conservative simply because there's no available evidence one way or the other about the effects of truly radical policies. For example, would a high citizens' income or market socialism work? As they've not been tried, we can't know.

 - If we are to base policy upon evidence we will have to override the public's preferences in many policy areas, simply because these are founded upon egregious errors. Whilst there is a case for doing this there is also a danger. Excluding the public risks increasing elitism and undermining the democratic spirit. Ignoring people's preferences might lead to a slippery slope in which governments eventually ignore people.

 - Instrumental rationality is not the only rationality. As Robert Nozick said, there is is also symbolic rationality; we do some things not because they fit a narrow cost-benefit calculus but because they symbolize who we are. We might want to criminalize drugs to express our abhorrence of wasting lives to addiction; or we might favour minimum wages even if they destroy jobs to symbolize our distaste for low pay; or we could subsidise inefficient green energy to express our concern for the climate. And so on. Whatever you think of these examples it would surely be rash to dismiss symbolic motives entirely, given that it is otherwise hard to understand why people vote or protest.

Now, I'm not sure how strong these arguments are. I mention them because both main parties attitudes to (say) immigration and fiscal policy are not based in evidence. Which must mean that there is some sort of argument against evidence-based policy.

Comments

[Money isn't everything]

Chris, when you say immigration policy is not based on evidence, I assume you mean on purely economic criteria?

There is undoubtedly a significant chunk of some immigrant cultures *cough* Pakistani Muslims *cough* who demand special treatment and privileges, won't integrate into our society, and bring unpleasant cultural practices, attitudes and beliefs with them.

Objection to SOME immigration, from SOME cultures, is perfectly rational if one values social harmony and the preservation of British culture and tradition more than a bit of extra cash for the exchequer.

Now this is definitely "symbolic rationality" as you say, but that doesn't mean it's illusory, or misguided, or false. The question is both valid and highly important as the polling indicates - what do you value more?

[Rick Crawford]

There is also the fact what people make of evidence depends on their prior beliefs. Ignoring this Bayesian fact, and going for a purely frequentist approach can lead to ludicrous conclusions and/or mutual miscomprehension. This is described well in chapter 8 of The Signal and The Noise by Nate Silver.
People talk about a statement like "there is no evidence that tougher laws lead to less drug abuse" as if it will persuade everyone against tougher laws. But if you already believe that tougher laws work, why would "no evidence" change your mind? (I'm talking loosely hear, but hopefully you see my point.)

[Rick Crawford]

*("here" not "hear", obviously)

[chris]

@ Money isn't everything. Yes - I did mean economic evidence and economics isn't everything. However, an empiricist would argue that the social harmony argument needs evidence too. For example if you believe the UK should be a Christian country, you might welcome immigration from Jamaica, Ireland or Poland.

[theOnlySanePersonOnPlanetEarth]

"There is undoubtedly a significant chunk of some immigrant cultures *cough* Pakistani Muslims *cough*"

And here is me thinking you were going to say American, with their NFL games at Wembley, their meals high in saturated fat and a culture that sexualises the young, among other things!

"who demand special treatment and privileges"

wow! Yes Muslims are like the new Aristocrats.

"won't integrate into our society"

Wow, yes I have never seen a Muslim in the workplace.

"and bring unpleasant cultural practices, attitudes and beliefs with them"

Wow! Yes you can't walk down a street in a Muslim area without seeing a young person undergoing genital mutilation.

"Now this is definitely "symbolic rationality""

No it's unpleasant, fascist irrationality.

"if one values social harmony and the preservation of British culture"

that horse has bolted I am afraid, see previous comment re influence of US culture on Britain. It is funny how British culture has been virtually colonised by US culture and all the far right can moan about is Muslims destroying British culture. God bless the em, they never let you down.

[Money isn't everything]

@Chris

What kind of evidence do you mean? As you've probably guessed, I'm no fan of Islam. That said however, I'm not really interested in immigrants' beliefs providing they

1) Are here legally

2) Accept British cultural norms and values

3) Integrate and mix with the locals (ie. those outside of their religious/ethnic/cultural group)

4) Contribute to society financially, ie. by working and paying taxes

It seems self-evident that deviating from those four points leads to social unrest - you don't need a weatherman to know which way the wind blows, etc.

[Money isn't everything]

@theOnlySanePersonOnPlanetEarth

Right, I must be an evil far-right racist. Obviously. Oh and a fascist as well, glad to see you got that in there too.

I'd stick to student politics if I were you, but thanks for your contribution!

[theOnlySanePersonOnPlanetEarth]

"Integrate and mix with the locals"

What about those white folk who live in gated communities? Should Muslims hang around the gates waiting for them to emerge so they can mix? What about those who send their kids to private school? Should Muslims wait outside these schools and engage with them at playtime?

"Accept British cultural norms and values"

What evidence do you have that they don't? i.e. Take us beyond your fascist imagination.

[theOnlySanePersonOnPlanetEarth]

"Right, I must be an evil far-right racist. Obviously. Oh and a fascist as well"

Well of course you should judge a person by their actions and not just their words but I can only judge you on what you say. For all I know you may not beat up dark skinned people, but based on your words, the evidence would point to you being politically on the far right.

This isn't based on student politics but an entire cannon of far right literature and history. You exhibit all the tell tale signs of a fascist. Your silly, yet dangerous generalisations are a big giveaway.

[Churm Rincewind]

@Chris - you say that "an empiricist would argue that the social harmony argument needs evidence too". Decades of polling show that the British public is disturbed by immigration.

What more evidence do you need?

[Pragmatist]

Of course there are situations where evidence is scarce yet a prompt policy decision is necessary. But even in those cases, policy makers should act in an informed way, combining theory and practice to ensure they are in a position to adjust policy in light of evidence of unforeseen harm etc. Or as John Dewey put it, they should engage in "intelligent practice versus uninformed, stupid practice".

[theOnlySanePersonOnPlanetEarth]

You know if Muslims had introduced us to trick or treat I'd swear there would be an outcry!

[El]

theOnlySanePersonOnPlanetEarth, you're boring.

[Dipper]

1. What you choose to measure and how you interpret it is strongly based in theory, so evidence-based policy is a mis-nomer.

2. Society is an evolving multi-variable system with many kinds of feedback and complex interactions. Predictive theories perform very badly in those circumstances, so evidence based-policy is a poor way to make decisions.

[Dave Timoney]

The evidence of history shows that if you suggest that 50 years of drug policy have been misguided at best and pernicious at worst, 6 months out from a general election, you will be thoroughly monstered by the press.

In that light, Cameron's response is not only rational but evidence-based. Similarly, Norman Baker obviously knows the LibDems are toast, so he wishes to establish his credentials as a compassionate reformer for future party jockeying, hence his interventions in FGM and now drugs.

He is playing a long game, which is also rational and, to the extent that politicians copy manoeuvres that have worked for others, evidence-based.

[e]

Your recent posts on confirmation bias, and cultural reluctants to recognise mistakes, are cogent reasons for being more than weary of evidence-based policy. And from the point of view of the ‘studied’, from the point of view of one who experiences evidence-based policy as being something that is applied as your due, via governments that are evidently picking and choosing their technocracy, it more than sucks. It negates politics.

[Keith]

The problem surely is that Politics is about ideology.

Ideology is not exactly the same as a religious faith but is quite similar.

A Liberal believes in a society based on Human Rights and freedom of private choice. So if liberalising recreational drugs leads to more deaths for example that is fine, we should be free to self harm! Die I must if I take too many pills or snort too much Columbian marching powder. The Utilitarian justification is that fewer other people will be harmed if we legalise drugs. Namely those people who do not take them suffer less harm or enjoy a gain. There would be less crime and or a tax bonanza as the druggie subsidises the abstinent who do not choose to consume mind altering substances. More revenue to allow free higher education or a UBI.

The issue is do we wish to give up the paternalistic duty of the state to protect us from our vices? How far do we really believe in Liberty as a moral good? That is surely not a matter of evidence but of Philosophical theory, of pure ideology. In the same way to give a example, is Torture allowable or not?

In theory Torture is totally illegal and there are no exceptions. But events of recent occurrence cast doubt on the commitment of the US and UK to apply the legal norm we subscribe to!

The validity of our fundamental ideological beliefs is not capable of determination by looking at evidence. As David Hume argued during the age of Enlightenment. Reason merely provides justification for what our passions dictate.

[Donald Smith]

Surely Labour's and the Tories' stances on immigration and fiscal policy are evidenced based. They're based on evidence of what will win votes.

If you accept this then the title of this post should be 'against evidence based attitudes' and the answers probably a combination of -

- limited knowledge and expertise of voters. most don't have the time or the skills necessary to assess the evidence

- natural human emotions, eg fear and distrust of the other

- the appeal of intuitive arguments, eg we're in a recession we must cut spending

I there's maybe 'supply side' factors here too in that Labour may be underestimating their ability to shift voter attitudes and/or trying to place themselves just a bit to the left of the Tories.

[theOnlySanePersonOnPlanetEarth]

"Evidence-based policy is, necessarily, conservative simply because there's no available evidence one way or the other about the effects of truly radical policies."

I think it works both ways actually. take the radical idea called fracking, when activists point out the dangers the fracking industry can turn round and say, there is no evidence that fracking pollutes water supplies, for example.

El - your comment is the ultimate in the pot calling the kettle black.

[An Alien Visitor]

"natural human emotions, eg fear and distrust of the other"

Is that a natural emotion in a world of ubiquitous communications? We are not living in the jungle anymore after all. But if we assume your point here, then everyone outside the village is an other. in fact, in this day and age, everyone outside the front gate is the other.

But seriously, there is nothing natural about it. If that were the case there would be no need for the daily mail :)

[Igor Belanov]

FATE- I think you're giving Cameron a bit too much leeway there. I strongly suspect that we could be four years, eleven months and thirty days from the next election and his response would be the same.
The problem is that, firstly, some people assume that different actors have the same end in view, and second, that where they do share the same end, that the most effective means will be easy to discover and implement. 'What works' used to be one of Blair's main slogans, but 'what worked' was never that obvious, and quite often proved to be abortive if it had to be implemented against the wishes of certain newspapers or business interests.

[Dave Timoney]

Norman Baker has now resigned and intends to spend more time with his constituents preparing for the general election. The charade continues.

http://www.independent.co.uk/news/uk/politics/norman-baker-resignation-the-letters--i-am-proud-to-have-served-in-your-team-9837195.html