Thursday, January 08, 2015

Republicans Have a Flux Correction Problem

This is ironic -- Congressional Republicans do not, of course, believe in climate change. In part, that means they don't believe in climate models.

The GOP recently voted to also start analyzing legislation by their economic effects -- so-called "dynamic scoring." Basically, you need to project out the legislation's impact on the economy over so many years.

Here's the rub -- the models used for dynamic scoring use aren't stable. They need to equivalent of "flux corrections" -- factors inserted to keep the model stable, instead of its variables running away to infinity. From Bloomberg Businessweek:


Flux corrections were a significant issue in the early days of climate modelling -- ad hoc, hand-inserted functions to keep the model from heading off to infinity -- think Manabe and Wetherald plus 20-25 years.

But flux corrections are no longer needed in most models: climate models are stable as time goes on (which is a different issue than parametrizations, which are simplifed functional representations of difficult-to-calculate-from-first-principles factors like clouds)

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Models for thee, but not for me. And the Republicans stumble blindly forward....

1 comment:

John said...

So, in terms of dynamic scoring the federal debt as a share of GDP cannot continue to rise.

I would suggest this is hardly a problem for the Repubs. Isn't reduction of the federal debt, for all the wrong reasons, clearly at the wrong time, their current obsession? They have no problem here, only ample justification to drive us over the cliff.

To me the irony is the economic analysis that is very concerned about unsustainable "federal debt trajectories" but, at its very base, assumes, and demands, always increasing GDP itself.

The hierarchies of NON-sustainability are reversed in importance.

Infinity for me but not for thee.

John Puma