The Case for Evidence-Based Policy

by Peter McLaughlin (Membership & Alumni Officer 2019/20)

We liberals are very proud of our commitment to evidence-based policy. It’s one of our favourite slogans and forms a large part of many of our political identities. The argument in favour of such a commitment is obvious: evidence is a good thing and ignoring it can mean missing potential unintended consequences. But there is resistance to the commitment, and it is not as uncontroversial as liberals would hope it would be. Specifically, it has been argued that it is an empty commitment, used to cover up otherwise disputable value judgments.

After the foundation of The Independent Group, two opinion pieces were published about the event on the Varsity website. One was one of the greatest Varsity articles ever about polarisation and partisanship, written by an extremely intelligent and good-looking philosophy student from Northern Ireland. The other was very critical of the new grouping, arguing that it stood for “the remains of a dying political class”.

One of the main points of contention the latter piece’s author had with TIG was their explicit commitment to evidence-based policy. “Do they seriously believe that other political organisations don’t use evidence?”, they asked. “A set of beliefs and values will always be necessary to assess information and formulate a political platform, no matter how anti-ideological they claim to be, because the evidence itself does not formulate policies.”

This form of argument is quite common in response to calls for more evidence in politics. It is true enough that evidence on its own cannot ever tell you what policy to support, only tell you what goals a given policy will achieve – you need values to choose between the goals themselves. The argument goes, then, that this means that “evidence-based policy” is an empty slogan. Everyone uses evidence, it’s said: all the real political disagreement is disagreement over values or ideology and appeals to evidence-based policy just disguise this fact.

This argument is worth addressing, because it is the strongest point against a commitment to evidence in politics. If it were sound, the liberal love of evidence-based policy would be at best pointless, at worst a red herring. Luckily for us liberals, it is not sound, for two reasons. The first is that its central contention – that everyone uses evidence to decide between politics, that all conflicts are ideological and value-driven – is simply false. The second is that, even if this premise were true, it would not follow that a demand for evidence-based policy is empty, because this demand has an important role to play in keeping our politicians more open and honest about their values.

Not all policies are evidence-based

The first response to the argument is that it’s strictly false. Many politicians advocate for policies that the evidence suggests won’t succeed in achieving their aims. “Easy fixes” have great political pull: to be seen very clearly to be “doing something” about an issue, even if that “something” is not what the evidence supports but can be enough to get voters on side. Meanwhile, evidence-based policy can often be technical and seemingly irrelevant, relying on complex mechanisms that are not immediately apparent; this can turn off voters and leave advocates stranded in technical discussions, unable to get to the meat of their ideological convictions. The pull of populism is always strong.

This can be seen very clearly by looking at the Green New Deal in the US, a bundle of policies that supporters claim is intended to tackle climate change. Anthropogenic climate change is probably the most important and pressing issue of our times, and it is beyond all doubt that not enough has been done to tackle it. The Green New Deal is not the solution so desperately needed. It ignores the large body of work that has been done on methods to tackle climate change: in its opposition to nuclear energy, cap-and-trade schemes, and Pigouvian taxes, it explicitly sets itself against the methods that the evidence supports. And the policies that are a part of the deal would either be ineffective or incredibly wasteful and inefficient. In their haste to fight climate change, Green New Deal supporters could in fact end up making it worse.

Crossing the Atlantic, we can see the same phenomenon in our own country. In their 2017 manifesto, Labour promised inflation-linked controls on rents, despite evidence overwhelmingly showing that rent controls create housing shortages and exacerbate supply crises, like the one the UK is experiencing currently. While complaining about ballooning inequality, their manifesto put more money towards policies like nationalising the railways, extending free school meals, and abolishing tuition fees (which would largely benefit the middle classes), than it would cost to end the benefits freeze that has swept hundreds of thousands into poverty, a policy the manifesto ignored. I have very little doubt that the Labour Party genuinely do believe in tackling inequality and creating a better life for the worst-off, and I applaud them for that. But, had they properly and impartially analysed the evidence, they would have seen that parts of their manifesto would not have been successful in achieving this goal.

By demanding of our politicians that their policies are evidence-based, we prioritise acting decisively over being seen to act decisively; we prioritise action over optics. This keeps this kind of populism in check, where in trying to look to do good, perhaps even in thinking they are doing good, politicians in fact fail to do good. This is enough to give the call for evidence-based policy sufficient weight and make it clear that it is not an empty slogan, but a meaningful demand. Yet committing to evidence-based policy can also increase the integrity of our politicians.

Honesty in Politics

Some Conservative politicians probably genuinely believed that the benefit cuts their party passed in government, especially after 2015, were necessary to strengthen the economy and will improve the lot of the worst-off in society in the long term. But I would bet that there were many who did not believe this. Tory MP’s had many aims in mind when considering benefit cuts: centralisation, smaller government, or even an opposition to a strong welfare state. But none of these were sold to the public. Benefit cuts were portrayed to the public as part of an overall package of austerity that was necessary after the overspending that occurred under New Labour became untenable after the crash of 2008. Whether or not that’s what most Tories believed, and whether benefits cuts would succeed in this goal, that is how they were marketed to the public.

The dishonesty embodied in this strategy – adopting a policy on the grounds of one set of values but pretending to have a different motivation – is destructive to democratic norms and representative government. Nonetheless, it is pervasive in politics, and our current political system strongly incentivises it. Any party that were to run on an explicit commitment to make the rich richer and the poor poorer, or to restrict civil liberties, or to reduce consumer choice, would do very badly in a general election; better, then, to say you’re tightening purse-strings, fighting terrorism, or protecting proud British industry. It’s a time-honoured tactic and can be found in every country through every generation.

How do we stop this? The answer is: widespread commitment to evidence-based policy. Politicians are only able to cover up their true goals because there is little pressure on them to demonstrate the actual effects of the policies, they commit themselves to. If politicians were put under pressure to show evidence that supported their policies, then presenting policies that were ineffective at achieving their stated goal (because they were not intended to achieve that goal) would be de-incentivised. By making evidence the standard to which we hold our politicians, we make honesty pay and strengthen our democracy.

None of this is to argue that evidence is everything, or that values and ideology have no place in politics. I don’t think a consistent liberal could or would say such a thing. Liberals value liberty (it’s in the name) and individuality; equal justice and an equal society; free speech and a free press; constitutional democracy, an independent judiciary and minority rights; open communities; an end to poverty and strong concern for the worst-off in society; and international cooperation. Liberals also have many disagreements among themselves over values: how should liberals feel about markets? nations? the family? Values and ends are important. But so too is evidence: demanding evidence-based policy is not empty, but is a demand for a more honest, more effective politics.