Friday, June 28, 2013

The United States of Innumeracy

Paul Krugman took apart a post by Erick Erickson, where the redstate blogger complained about a range of things, including, "the price of a gallon of milk and loaf of bread that keep going up though Ben Bernanke tells them there is no inflation."

Krugman answered with two charts, taken from the Bureau of Labor Statistics, which is the entity charged with gathering price information and calculating inflation:


The comments were ... interesting. People commented with higher prices where they live. Fair enough, but it doesn't disprove the data Krugman presented, which are national averages--some places are always going to be more expensive than others.

Other people reported prices going higher where they lived, which is more interesting, but hard to know what to make of without additional info.

But what really struck me were the number of people saying some version of, "Look at those charts! Those prices are going up!"

Well, the prices now are higher than the prices at the beginning of the charts, in January 2003, but look again at what Erickson wrote:

the price of a gallon of milk and loaf of bread that keep going up though Ben Bernanke tells them there is no inflation
I don't see any reading of that other than implying that prices are currently rising, and they're clearly not. Bread spiked in the middle of 2011, but it's been right around $1.40 since spring of 2008. Milk is higher than it was in the middle of 2009, but lower than in the middle of 2008. Those charts really give no evidence of any current rise.

Others comment (correctly) that a loaf of good bread might be $4, but read what the chart says: "Bread, white, pan, per pound." If you're looking at a 24-oz. loaf of quality bread, don't expect to pay $1.40 anywhere. (It's a real problem that the only bread some households can afford is of low quality, but that's not the problem that Krugman's talking about, and I suspect it's not what Erickson meant either.)

For my money, as it were, the most disheartening comment was from a user with the handle oldchemprof:
But, Professor Krugman, you own chart shows that bread cost 40% more since Obama became President than it was was when President Younger Bush took office.

What are we to think about that.

Well, other than the fact that it's not true? Lord help this person's students if he/she actually is/was a chemistry professor and is that incapable of reading a simple time-series chart. The students should ask for a refund.

Unless the issue is that oldchemprof simply doesn't know when Obama became president. In which case, it's all good, and their $40,000 tuition was totally worth it.

In the spirit of President Younger Bush, Is our voters learning?

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