Science over Politics

The media tend to present scientists as super-rational beings, who stand outside the cognitive biases they note in others. For example, the paragon of rationality Carl Sagan famously wrote:

In science it often happens that scientists say, "You know that's a really good argument; my position is mistaken," and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.

I think this is profoundly misleading, because I can't remember any occasion where some scientist, on the spot, changed his mind about something important. They might concede a minor plank, but never the big idea. Inconsistent data points are seen as fatal or noise depending on what side you are on. Almost all interesting economic phenomena do not have definitive proof, so basically most of what we argue about comes down to common sense, just as in political or moral debates. After all, we only have a handful of recessions, and the effects of deficits (say) on unemployment (say) depend on whether the economy was at full employment, and whether the spending was an automatic stabilizer or exogenous increase, etc. Basically, we are left with about 2 datapoints to extrapolate from, and these also had their own idiosyncracies (especially if one is old enough to remember them personally).

The objective standard errors on important policy disagreements basically allows one to have any belief they want on fiscal policy. That doesn't mean everyone is equally right/wrong, just that it's essential to have good prejudices, opinions on things that can't be proven from axioms. This is why the academics aren't much help, because IQ and education just allows one to distinguish what is true, false, or indeterminate, and not very good at establishing probabilities. That is, a good statistician like Joshua Angrist will have a chapter on nonlinear relationships, and how important they are, and then argue that a 2% wage increase from when kids started school has implications for spending more on college; or Paul Samuelson will continually beat the drum for more deficit spending, and when someone mentions he is encouraging a debasement of the currency he will mention that he acknowledged that governments could spend too much, so he has done no such thing.

Priorities, not truths, underlie common sense.

The main advantage of scientific as opposed to political debates is that you don't have to be democratic, the mob does not rule.