矮油，你是“折扣黨”吧？碰到1塊9毛9，就堅(jiān)決不買2塊的。但從質(zhì)量上考慮，你會不會覺得2塊得東西會比“1塊9毛9”的東西好呢？

“Economics: supply and demand.”

That’s Father Guido Sarducci...

“That’s it.”

…sharing the entirety of the economics course at his Five-Minute-University. Of course, the market forces of supply and demand are supposed to be the main factors in setting the prices for goods and services. But marketing comes into play as well. Supply and demand have little to do with a seller’s decision to price an item at $19.99 instead of 20 bucks.

The psychological trick of seeing a one instead of a two at the front of a price, as in $19.99 versus $20 can work to increase sales. But Robert Schindler, professor of Marketing at Rutgers School of Business-Camden, says that in some cases, the penny saved isn’t worth it.

The $19.99 technique may actually backfire when a consumer is most concerned about quality, say, in a luxury item. The penny-lower price can then raise questions in the buyer’s mind about quality. According the Schindler, in those cases, the full, round non-99 price may send a signal of a better buy.

—Steve Mirsky