What is the Oxford comma, and when do I use it?

The world of punctuation, for the most part, is an uneventful one. Few people have ever lost sleep, or friends, or millions of dollars over the use of a full stop or a question mark. There is one controversial mark, however, which not only excites impassioned debate but has certainly lost at least one company millions of dollars: the Oxford comma.?

Named after its early adoption by the Oxford University Press in the early 20th century, the Oxford comma (or serial comma, or Harvard comma) is designed to be used before the last coordinate conjunction (and/or) in a list of three or more things.? For instance, the sentences “I’d like to thank my parents, Donald Trump and Taylor Swift” and “I’d like to thank my parents, Donald Trump, and Taylor Swift” are very different. Without that final comma in the second sentence, it could be read as if the parents in question were Donald Trump and Taylor Swift, which is how the first sentence reads.?

Fans of the mark say it plays an important role in clarifying lists whereas others avoid it because it feels clumsy, and instead argue in favour of restructuring (“I’d like to thank Donald Trump, Taylor Swift and my parents”).?

Whether the Oxford comma is either useful or necessary is still a matter of ongoing debate. As the Oxford Companion To The English Language notes, the Oxford comma can avoid ambiguity but there are also cases where it can introduce ambiguity. Whether or not it’s recommended in stylistic guides is split across the Atlantic: US style guides (the Associated Press aside) tend to require the Oxford comma while the UK style guides (the Oxford University Press aside) recommend avoiding it unless it is actively required.?

An Oxford comma can cost you millions of dollars?

Most debates around the use of the Oxford comma are held in academic circles but use of the mark, or rather its absence, has also had some serious real-world implications; in one such case the omission of an Oxford comma cost a company in the US millions of dollars.?

Back in 2017 a dispute erupted between Oakhurst Dairy and a group of drivers regarding a law in Maine which laid out the rules around overtime payments. The law stated that the following activities do not count for overtime pay:?

“The canning, processing, preserving, freezing, drying, marketing, storing, packing for shipment or distribution of:?

(1) Agricultural produce;?

(2) Meat and fish products; and?

(3) Perishable foods.”?

Drivers in the state managed to successfully argue to the US Court of Appeals that they were owed overtime pay because there was no comma after “shipment” and before “or distribution” – they were paid US$5m. David Webbert, the lawyer who helped bring the case against Oakhurst Dairy, told reporters at the time that the inclusion of a comma in the clause “would have sunk our ship”.?

Conclusion: choose your style??

It is a stylistic choice whether to use the Oxford comma – if you are following a style guide make sure you stick to it carefully. If you are writing yourself and you are going to use the Oxford comma, just make sure you are consistent.?

For me, if the twin goals of great writing are clarity and brevity, it’s probably better to avoid Oxford commas. If you’re worried about any ambiguity in a list, it may be better to restructure your words altogether: at the very least you’ll know you’re doing your best to head off any potentially expensive lawsuits.?