[JohnnyZ]

You can bet if the too high prices outnumbered the too low prices that would have made the story in foot high print. Since that ratio is not given, you can bet that most of the time the California WalMarts were charging the customer too little.

"The researchers said the average cost of overcharges was more than that of undercharges."

Back in the day I went through an entire Wal~Mart checking prices in preparation for inventory. There weren't a WHOLE lot of wrong prices but I wouldn't be surprised by 5% in some stores. It's a matter of overworked department managers keeping up with price changes. The error was very rarely on the checkout end.

[Common Tator]

The researchers said the average cost of overcharges was more than that of undercharges

That is way to fool you again.

There could be 90 undercharges and only 10 overcharges and their statement could still be true. As in the following example.

Say the 10 overcharges were 2 dollars each.. For an average over charge of 2 dollars and a total over charge of 20 bucks.

Say each under charge was 1 dollar for an average undercharge of 1 dollar. The undercharges would total 90 Dollars.

The undercharges in my example totaled 90 dollars while the Overcharges totaled 20 Dollars yet the average overcharge was twice as great as the average undercharge.

Printing "The researchers said the average cost of overcharges was more than that of undercharges." is just a way to not tell the whole truth.