Behind Absense of a Comma
- Series of words:
- We read novels, stories, poems, and plays.
- Series of phrases:
- We went to the beach, to the mountains, and to the desert.
- Series of clauses:
- We swam at the beach, we hiked in the mountains, and we admired the desert.
There is another comma style called The Journalistic No-Last-Comma Style and the reason of why this style exists is amusing but reasonable.
"The Journalistic No-Last-Comma Style: Why do some writers leave out the comma between the last two series elements? They do so because that style was developed by newspaper editors in the days when every comma cost them another tiny slug of lead. They actually saved lead, space, and money by deleting the last comma in every series throughout their publications! They figured that the coordinating conjunction was enough to mark that boundary."
However, this style is not recommended in academic writing because without the last comma, the meaning can occasionally be ambiguous.
"We invited Mike and Janet, Cheryl and Jim, Claire, Leon, Lewis and Marie."