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Sunday, April 28, 2019

Barry Barry Ritholtz asks how the New York Times got 2 very different figures from the same data

Barry Ritholtz has doubts about data presentation at the New York Times

His commentary is very brief "What is this about? Is it guilty conscience, or something else?"

The graphs are strikingly different


Alberto Cairo explains

I have a guess about what happened. I guess the second figure is a regression with counties weighted by population and the first is unweighted. I consider both semi reasonable things to do, but weighting to be better (it is also the second to be produced if I understand correctly)

First the fact that the size of the circles depends on total votes in the second figure suggests that the regression was weighted by total votes. Second it is clear that the big blue counties pull the line more in the second figure. I note that the estimated effect of government assistance on the Trump vote is greater in the second figure.

Others have another guess -- that the first line was hand drawn after eyeballing and isn't a regression line. That seems unlikely to me. Someone tweeted that it is clearly not an OLS regression. I suspect that the eye is even more influenced by outliers than OLS is. The dense cloud of many fairly similar observations does not impress us as much as it impresses a computer running OLS

I think I'm going to give a hostage to fortune and guess that, if someone sends me the raw data, I can run an unweighted OLS regression and get figure 1. I feel pretty safe, because I am pretty sure few people will read this and none will download and e-mail the data to

Reply to PGL comment on Brad DeLong Post on Stealing Candy From Fish in a Barrel

This is a comment on a comment and is here only because I can't insert a figure in a comment section. Click the link. Good point. Also the GOP supply side story is about non residential fixed investment. They have been promising for 39 years that their tax cuts will cause a huge increase in business investment and that Democrats' tax increases will cause it to collapse.

Also there has been a very clear pattern, which happens to be the exact opposite. The ratio of non residential fixed investment to GDP is high when a Democrat is in the White House (especially if he is a peanut farmer from Georgia) and collapses when a supply-sider is in the White House.

The pattern is so clear that it is hard to avoid seeing it. The incentives to claim to have managed not to see it are clearly very strong.

Also Brad why real/real. Two famous economists have stressed that the causes of high investment cause high nominal/nominal while effects are due to real/real so one can test causation using relative prices. One of them is named DeLong. The tax bill doesn't affect the relative price of capital goods, I think it is best to look at dollars/dollars and leave price indices out of it.

Thursday, April 25, 2019

Houston Houston can you read me giving a hostage to fortune

Who told Kay Steiger that I don't read Raccoona Sheldon AKA James J Tiptree Jr I-m not actually sure that's who she accused her readers (including me) of overlooking. I just have this
OK so now I click Bingo "Sheldon primarily wrote under a male pseudonym — James Tiptree Jr."