Thread by @rationalhill

Back in January I asked whether it was safe to talk about economic policy again (intellidex.co.za/insights/stuar…). @Bruceps has highlighted that some policy arguments, particularly from the left, still play straight into the hands of the state capture brigade businesslive.co.za/fm/opinion/bru…

There has been a furious response to @Bruceps 's point, arguing that we can all stand against state capture while still engaging on policy, including by @IfaaCT for example: businesslive.co.za/amp/bd/opinion…

A healthy policy debate is very important. But it is all too often afflicted by ideological posturing and "pressure groups" for whom the facts are not important. This is obviously not an SA problem alone. So we should look at how good policy outcomes are developed elsewhere

I've seen top-level policy engagement in action, though it is usually within academic settings. The discipline of journal publishing, academic conferences, engagement with peers, leads to the testing of evidence and ideas.

The 1000s of researchers working in economics around the world also are able to spend time on gathering evidence. Now @Bruceps says that economics is not "a science". I disagree. His claim seems to be that economics cannot run experiments.

For the most part, neither can cosmology, but we don't deny that Galileo was a scientist. He spent his time observing the heavens to find evidence for Copernicus's theories. No experiments. A lot of economics works like this - creating hypotheses and then looking for evidence

Plus, economics can run experiments, though it is tricky. Auction models are built by running computer simulations and small scale real world trials. Different forms of welfare systems have been tested at local level before wider implementation

Our own trial sites for the National Health Insurance scheme are a kind of experiment.

I am in agreement with @rodrikdani that there is no single methodology in economics. We use models a lot and their applicability varies depending on the situation. For the most part they are ways of understanding tendencies that may be at work in any particular situation

Models are a kind of hypothesis. But it is the data that really separates the wheat from the chaff in our efforts to know whether a proposed explanation for a feature of the economy is a good one.

The academic environment does a pretty good job of foregrounding evidence. Bringing evidence, and a set of models that explains it, is your ticket to the debate. Evidence-free ideology simply doesn't get into the room.

One problem with the way we do economics in SA is that we don't have these rules of the game. That makes it unclear who we should listen to. As a result the public can't easily separate the serious social scientists from those pursuing different agendas

Evidence is not the preserve of the left or the right. There are plenty of excellent economists on the left who are evidence-based just as there are economists on the right who ignore evidence. E.g. @PikettyLeMonde and @JosephEStiglitz foreground evidence

Some on the left proclaim evidence-based reasoning is itself a suppression of their ideas. This meta point is unconvincing. I think we can be unorthodox about the type of evidence, while being orthodox about the importance of evidence.

In my experience, the evidence-based reasoning on the SA economy is mostly found within "orthodox" approaches. The volumes of excellent research published by the @SAReserveBank 's economists, for e.g., are strongly persuasive in showing why inflation targeting is important

Those who disagree should engage with that work, identify the points at which it goes wrong, and the cite the evidence for alternative models. Those are the terms on which we should engage.

One final point: public policy is not about evidence. What outcomes we desire as a society are ideological. But the means to those is a practical issue. The effect of policies is the question social scientists can answer.

Further reading: Nobel laureate @UncertainLars provides great insight on the tricky issues regarding theory and evidence in public policy debates review.chicagobooth.edu/economics/2019…