Absurdly Driven looks at the world of business with a skeptical eye and a firmly rooted tongue in cheek. 

Four big airline groups have the America's skies largely to themselves.

They own more than 80 percent of all the available seats.

And if you call what they do competition, then it's not quite the NBA's Western Conference.

So when any of the Big Four starts kvetching at some of the others, it's cause for fascination.

Last week, I wrote about how Southwest Airlines' chief revenue officer, Andrew Watterson, described his rivals' Basic Economy offering--featured, for example, by Delta, United, and American--as "substandard products."

This week, I hear of another, well, difference of opinion between Southwest on one side and United and American on the other.

As Skift reports, the Department of Transportation produces figures every year for which airline loses the most bags.

It has always been calculated by dividing the number of passengers that flew on the airline by the number of bags reported by passengers to have gone AWOL.

This is about to change, as it doesn't really paint an accurate picture.

That's because it doesn't count all the bags that get checked at the gate, those that came from a different airline, and those that get checked when you're already on the plane.

So now the new math will involve dividing the total number of bags carried by an airline with the number of bags lost.

To a lay mathematical eye, it seems logical.

Southwest has a particular issue here.

Because it doesn't charge for the first two bags, it often ends up with the most bags lost.

After all, when you can check bags for free, you're more likely to,

Ergo, Southwest carries more bags than its rivals. On official tallies, that is.

And further ergo, there are more likely to be more customer reports of lost bags.

On United and American, which charge for checked bags, passengers are more likely to chance getting the bags on as hand luggage. 

If they don't get away with it, those bags are checked, but not necessarily added to the official baggage tally.

So the DOT is asking airlines to install better equipment to make sure the baggage number is accurate.

You may enjoy this delicious quote from United and American offered to Skift: "No party has convincingly demonstrated that the government has a legitimate role in a deregulated industry of requiring airlines to report this service metric."

Some might choose to translate this as: "It's nobody's business how often we lose passengers' bags."

And here's Southwest's view, offered to Skift by its senior attorney Leslie Abbott: "Right now, the metric is out of date and highly misleading. It compares two numbers that are unrelated to each other."

Yes, the airlines are fighting over data, because they know that the data matters to some customers.

Indeed, this all comes at a time when Airlines for America, a lobbying group that represents, among others, Southwest, United, and American, is fighting to make it harder for customers to see data such as on-time percentage and cancellation rates of various flights.

Oddly enough, Southwest isn't so magnanimous about all its data being given to consumers by every means.

It doesn't share its fare data with third-party sites such as Kayak and Expedia.

You can only book on Southwest's own site.

Still, it insists it's better at math. So that's something.