Do you put a comma before “and” in a list? Should you? Can you finally correct your persistent coworker/friend/spouse once and for all?
Sadly, no. They’re both correct.
Here’s the difference: The Oxford comma (as in “Dancer, Prancer, and Vixen”) is used by the Oxford University Press and is recommended in the Chicago Manual of Style. Academia and most traditionally published books follow this rule, always inserting a comma before “and” in a list of 3 or more for the sake of clarity. The Associated Press, however, recommends ditching this comma for the sake of space (as in “Dancer, Prancer and Vixen”) only using it when necessary for clarity’s sake (as in “grilled cheese, peanut butter and jelly, and turkey sandwiches”). Following this guideline, newspapers, advertisers, and some websites often skip the Oxford comma.
Deciding when to use it and when not to seems silly to me, so I use the Oxford comma in most situations (see the previous sentence). But really, as long as a writer is consistent in his or her choice, either form is correct.
Questions? Let me know!