[temphn]

Ha. Methinks you doth protest too much. But I'll be very precise. Show me the equations and code that Krugman wrote in 2009 that predicted the unemployment curve over the last four years. OMB (full of economists!), to their credit, at least essayed a quantitative prediction. As the first graph showed, it was completely wrong.

So: what "very old" models performed "very well"? You must be thinking of something here. I'm not talking about a Krugman blog post where he says the stimulus was too small. I'm talking about an actual scatterplot, a time series prediction with the X axis as time, the Y axis as the dependent variable, and actual empirical measurements plotted vs. the predictions of theory.

Here is another example from a different field:

http://www.nature.com/news/climate-change-the-forecast-for-2...

http://www.nature.com/news/499139a-i2-0-jpg-7.11335?article=...

You can see the graph halfway down the page, with theoretical predictions as the red line and actual empirical measurements as the black line. The Nature article admits they don't match well. But in other fields they do match well. For example:

http://physics.info/projectiles/practice.shtml

In ballistics the predicted time series match experimental results very closely. So I ask again: what "very well established models" in economics performed "very well"? Which of them nailed the curve?