Call it what you will: the serial comma, the Oxford comma, or the Harvard comma. It is the cause of much consternation to writers and editors. It causes fights in bars (okay, discussions in libraries). Devotees of the Chicago Manual of Style insist on its use. Those who adhere to Associated Press style consider it superfluous. And there are those who say that it doesn’t matter whether you use the serial comma or not, so long as you are consistent.
I have always been a believer in the serial comma because I think that it eliminates the possibility for confusion. If you’re looking at a list of 1, 2, and 3, it’s clear that 1, 2, and 3 are three distinct items. Consider the example of this hypothetical book dedication from the Chicago Manual of Style:
With gratitude to my parents, Mother Teresa and the pope
You can picture the editors of the Chicago Manual of Style chuckling smugly at the notion that without the serial comma, readers might think that the hypothetical author’s parents are Mother Teresa and the pope. The absence of a serial comma might cause the reader to think that “Mother Teresa and the pope” is one unit equal to the author’s parents. As a believer in the serial comma, I’m laughing right along with them.
If you look at the popular style guides that do not use the serial comma, they are mostly related to the news industry (Associated Press, The Times, The New York Times, etc.). As a former journalism student and journalist, I can tell you that many styles espoused by newspapers are designed more for conserving ink than for clarity of writing (that’s why you see single quotes used in headlines instead of the more correct double quote). The style guides that call for the serial comma (the American Psychological Association, Strunk and White’s Elements of Style, and the Chicago Manual of Style, to name a few) are more concerned with clarity of writing.
Opponents of the serial comma will argue that it can sometimes actually cause confusion rather than clear it up. A surprisingly engaging and in-depth entry on Wikipedia uses this example, again a hypothetical book dedication, this time inspired by editor and writer Teresa Nielsen Hayden:
To my mother, Ayn Rand, and God
Here, the reader might believe that Ayn Rand is the author’s mother when the serial comma is used, but without the serial comma, the confusion is eliminated (“To my mother, Ayn Rand and God”). I argue that you have to work a lot harder to create a scenario where the serial comma causes confusion rather than eliminating it. Another example from the same Wikipedia entry is this:
My favorite types of sandwiches are pastrami, ham, cream cheese and peanut butter and jelly.
Without a comma after “cream cheese,” the reader is not sure whether the peanut butter belongs with cream cheese or jelly. With that, I’m off to the library to pick a fight with a journalist and then go out for cream cheese and peanut butter sandwiches.