Should “data” be singular or plural?

For more than a millennium after the fall of Rome, educated Europeans were distinguished by their knowledge of Latin. One of the three subjects of the trivium—the basic tier of a classical education, itself based on a Roman model—was Latin grammar. Europeans have long since stopped writing primarily in Latin, but learned people are still expected to be able to deduce that to “decimate” means to destroy a tenth of something (a mutinous legion was punished in this way), or sprinkle annus mirabilis and mutatis mutandis into their speech.

It is not for lack of knowledge of, or affection for, Latin that The Economist marks a change this week. The reform involves one of the most curiously polarising issues an ending on a foreign word has ever generated in English. We will now allow singular use of data alongside the plural. Specifically, when considered as a concept—as in data is the new oil—the singular will be acceptable, as well as when the data in question is considered as a mass (the data on this mobile-phone plan is insufficient). However, when data points are considered as a group of pieces of information, the plural should still be used: data from the National Oceanic and Atmospheric Administration indicate the hottest summer of all time.