Oh My God! 40% of Sick Days Taken on Monday or Friday!

I thought this was kind of funny, from the false hysteria department.  The Arizona Republic begins ominously:

If you're already mad about gas prices, prepare to get madder.  Besides paying prices at the pump that were unthinkable a few months
ago, many consumers also are getting ripped off by the pump itself.

Uh, Oh.  I can see it coming.  The AZ Republic has smoked out more evil doings from the oil industry.  I shudder to think what horrors await.

About 9 percent, or about 2,000, of the 20,400 gas pumps inspected this
fiscal year by the Arizona Department of Weights and Measures since
July 1, 2007, failed to pass muster.

Oh my freaking God!  Every fill up, I have a one in 11 chance of my gas being measured wrong.  I just bet those oil companies are coming out in the night to tweak the pump so I get hosed. 

Half of those were malfunctioning to the detriment of customers.

See!  There you go!  Half are to the detriment of customers! 

Oh.  Wait a minute.  Doesn't that mean the other half are to the benefit of customers?  Why would those oil guys be doing that?  This sure isn't a bunch of very smart conspirators.  Could it be that this is just the result of random drift in a measurement device, with the direction of drift equally distributed between "reads high" and "reads low"?

As it turns out, I worked for a very large flow measurement instrument maker for several years.  For a variety of reasons, flow measurement devices can drift or can be mis-calibrated.  To fail the state standard, the meter has to be off about 2.5%, which is about 6 tablespoons to the gallon.  State governments have taken on the task of making sure commercial weights and measures are accurate, and though I think this could be done privately, I don't find it a terribly offensive government task.  Having taken this task on, it is reasonable to question whether it is doing its oversight job well.  But let's not try to turn this into a consumer nightmare by only discussing one half of the normal distribution of outcomes.

Post title stolen from an old Dilbert cartoon.


  1. ErikTheRed:

    You could always write them a letter implying that half of their reportage is below average (although below median would be more technically correct, I suppose, but then again I suck at math). See if it gets the point across.

  2. Josh:

    It's usually fun to see reader comments attached to goofy stories like these... but in this case, it looks like the Arizonians have blindly bought into the story. Only a couple of commenters point out the mistake, and there are others who disagree! Very sad.

  3. Dan:

    This misplaced anger at the oil companies is easy to understand. Americans have been told all their lives that they have a God-given right to cheap gasoline. Now that it's not so cheap, they feel they have to have a scapegoat, and politicians in both parties are eagerly stepping in to stir peoples' anger to avoid having to take responsibility for their own lack of action on energy issues the last 25 years.

    I don't think most Americans understand basic economics - supply and demand and the ability of companies to price products. Do they really believe that after decades of $1 a gallon gas, the oil companies got together and conspired to raise the price to $4 a gallon, thinking no one would notice? Do they actually believe such a plan would be possible to carry out? It seems ludicrous, but I think that at the core, that's what most people think.

  4. Ed:

    I worked as an engineer designing gas pumps for years and find it difficult to believe that a gas pump is even capable of a error as large as 2.5%. What is not uncommon is errors that large and larger from the people who are appointed to check the pumps. In my experience they have little if any training.

  5. DKH:

    Maybe this is a sign that it would be a better idea for colleges to require statistics classes rather than diversity classes.

    There seem to be two big groups (of the AZ Republic commenters):

    1. Those that think the corporations are screwing them over.
    2. Those that think the government is screwing them over.

    There are others outside of the groups, but neither of these groups really comes out looking good.

  6. Mike:

    They do articles like this every year. They usually have the article that talk about how gasoline in the summer has less energy per gallon then in the winter, when it's cold.

  7. tom:

    Do you want to bet how many 'sick days' are left untaken when they are mandated by the government?

    IIRC, one state (CA?) is looking into mandating that every shop with more than X employees grant a fixed number of sick days.
    Sick days are just extra vacation days scattered on Mondays and Fridays...