Limits of evidence

Twice in the space of a few days the government has over-ruled the recommendations of its expert advisors- on prisoners’ pay and on the classification of cannabis.
Which raises the question: what role should empirical evidence have in policy-making? Here’s a theory - very little.  Evidence-based policy-making (EBPM) is a sham. I say so for four reasons:
1. It’s undemocratic. The evidence might tell us that tough sanctions against cannabis use are counter-productive in cost-benefit terms. But the public seem to want such sanctions. And they are not necessarily irrational to do so. Instrumental rationality isn’t all that matters. So does symbolic rationality. Being “tough on drugs” symbolizes the sort of people we are: clean, self-disciplined, sober. It might be important to demonstrate this, even if it is costly to do so. EBPM is wrong to assume that utilitarianism is the only standard by which to judge policy.
2. Evidence is often unavailable for policies whose main justification is the long-term effect they’ll have. Would a roll-back of the welfare state lead to an end of a culture of dependency? Would greater democracy lead to a more energetic and socially-engaged citizenry? Compelling evidence on these questions is lacking - and would be for years even if such policies were implemented - because it would take decades for these effects to be felt, as it can take generations for social norms to change.
EBPM therefore has a bias towards incremental changes to the status quo. It’s small-c conservative.
3. Evidence is little help in policies designed to tackle low-frequency events.  It’s now widely thought that the UK’s banking regulation policy has been inadequate since 1997. But we went 10 years without realizing this, simply because the test of it - a banking failure - didn’t happen until Northern Rock collapsed. Evidence can only inform banking regulation by telling us how we could have stopped the last failure.
Or take another example - anti-terrorist legislation. There’s no evidence that banging suspects up for 42 days without charge would prevent terrorist attacks. But is this because the policy is useless? Or is it because there have been so few attempted attacks anyway? On the evidence, we can’t tell.
4. EBPM cannot adjudicate between values: liberty vs. security, or equality vs. prosperity, say. At best, it can only tell us the costs of the choice.
Herein, I think, lies the real damage that EBPM can do. In the wrong hands - and policy-making is usually in the wrong hands - it can be used as a way to disguise what is really a value judgement:  supporters of the “20 reasons for 20 weeks” campaign are accused of doing just this.
But the fact is that policy-making must be about choices of values, usually in conditions where evidence is missing or inconclusive.  Politics cannot be a pure science, guided merely by facts, logic and evidence. And insofar as EBPM pretends otherwise, it does violence to the very meaning of politics.

Comments

[kinglear]

To a certain extent, policy is dictated by " what can you get away with" and then a pressure group wants something - so you give in to them. This is roughly what was happened over cannabis

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Winston Churchill comes to mind:
"It is a fine thing to have good intentions, but it is also very important to be right."

[Larry Teabag]

[Being “tough on drugs” symbolizes the sort of people we are: clean, self-disciplined, sober] hypocritical, moronic, bossy ostridges.

I'm not sure 1 works. If the electorate voted in a fascist party, "democracy" wouldn't be a reason to support fascism.

As for 4,

[it can only tell us the costs of the choice]

but this is vital information isn't it? Particularly in the case of the war on drugs where the choice is (a) a policy which is preferable by any practical measure, versus (b) amazingly expensive and illiberal posturing.

[Robert]

This seems to be Hillary Clinton's rationale for her Gas Tax holiday. No economist can be found to support it, which is being spun as a good thing. All those elites are out of touch, you see...

[jameshigham]

But is this because the policy is useless? Or is it because there have been so few attempted attacks anyway?

Plus a certain amount of internment is factored in.

[Rob]

Who provides the evidence?

'Experts' reserve the right to change their mind and historically they do. Depending on where you place your money, so you can get an argument for any particular viewpoint you wish.

Isn't that how governments use experts in any case?