Back when the Obama Administration was blabbering on about “green shoots”, the forefather of the confidence fairy, I repeatedly bemoaned the confusion between the change in unemployment or other economic indicators (the first derivative) versus the number of people actually unemployed. Equally awful was the fixation on the second derivative: the rate at which the first derivative changes (i.e., the speed of the change). Because a minor change in the amount of a whole lotta suck is still a whole lotta suck.

By way of a longtime reader, we discover that, two years after I demonstrated basic mathematical literacy, wunderkinder Matthew Yglesias has stumbled across the same point:

Here’s the way I think the Obama administration saw it:

That’s a steep downturn at the end of the Bush administration followed by a sharp recovery. Verdict: Our crisis intervention measures worked, and the conditions for future growth are set. Here’s the way they should have seen it:

This is a steep decline at the end of the Bush administration, which slows and then ends. Verdict: Our crisis intervention measures worked, but now we’re at the bottom of a big ditch and need a new set of measures to climb back to the top.

This is not hard. It wasn’t even difficult to notice while it was happening (I did after all). Though I suppose one part of the pundit’s art is to point out the obvious and make said pointer seem brilliant.

You know, I should get paid to wite this stuff. Or something.