The New Yorker magazine, The Chicago Manual of Style, Strunk and White, and most book publishers in the U.S. favor the serial comma. The New York Times, the Guide to Canadian English Usage, most British writers and publishers and The AP Stylebook make a practice of omitting the serial (or Oxford) comma unless it's needed to avoid ambiguity.
Authors, publishers(,) and style guides have long disagreed about the need for a comma before the final and in a list. In the September 1894 issue of The Writer magazine, editor William H. Hills illustrated the value of the serial comma:
The necessity of using the comma after the next to the last of three or more adjectives in succession, when the last two are connected by a conjunction, was pointed out by E. Lincoln Kellogg in the July Writer. An excellent illustration of the rule is afforded by the following sentence, which I came across in a story yesterday: "He was a noble fellow--wonderfully versatile, brave, and generous to a fault." If you omit the comma after "brave," you say that the hero in question was brave to a fault, which is not what the author meant.
Again, take this sentence: "For dinner he had lobster and vinegar, and cherries, and terrapin, and bread and milk." All the commas used are absolutely essential, to give an accurate idea of the tempting repast. It will be observed that the use of "and" does not make the commas unnecessary, a sufficient answer to the assertion sometimes made that the comma after the second adjective in a group of three of which the last two are connected by "and " is unnecessary because the "and" takes the place of it.
w. в. н.
For what it's worth, we agree with Mr. Hills. Unless you're employed by an American newspaper or writing for publication in Canada, Australia, or the U.K., make the most of the serial comma. As New Yorker editor Harold Ross once said in its (and his) defense, "We're right, and all the rest are wrong."
For further discussion of this persistently controversial mark, please see What Is the Oxford (or Serial) Comma?
More About Punctuation:
Comments
When does the serial comma come after the conjunction?
Take these questions: “Our questions are, what date will you arrive? where will you stay? and, do you desire us to furnish transportation?”
The classic case for the serial comma is: “I would like to thank my parents, God and Mary.”
Levi, the apocryphal quote is actually “I would like to thank my parents, Ayn Rand and God.”
But you must bear in mind that a lot of people mistake the comma for a breath. If you imagine reading some sentences, where people would pause for a breath or to consider the next section, there is a comma.
Sometimes I believe that the serial comma before an and is needed, but more often than not, it is not.