The feds have regulated the size of your liquor bottles since the 1930s, when Prohibition was repealed. The U.S. Congress gave the agency that would become the Alcohol and Tobacco Tax and Trade Bureau (TTB) the authority to regulate bottle sizes for two key reasons: To prevent sellers from deceiving consumers by shorting them. And more critically, standard sizes made it easier to track federal taxes companies owed on liquor they sold.

Regulations rolled out in 1934 and 1936 that designated a roster of imperial units that could be used to sell liquor. That included the familiar quart, pint, and fifth (a fifth being a fifth of a gallon), but also oddballs, including a 1/16th pint (that is, an ounce), which was available only for brandy. The feds allowed 38 different bottle sizes.

So why was the 700ml bottle added to the metric family last month? Blame a global coalition. In this case, distillers, distributors and exporters all pressed for allowing new sizes. It wasn’t a new attempt—Washington state, for instance, lobbied for the change back in 1987, arguing that the restrictions on size stifled price competition. The feds didn’t agree back then.

This time, those pushing anew for change argued that the United States had become an isolated island of 750ml bottles amid a sea of 700ml bottles—the standard size most everywhere else in the world. (India is one other significant 750ml island.) So those wanting to export liquor—from either the U.S. to Europe, or vice-versa—had to order two sets of bottles and calibrate their equipment for two separate bottling runs. That was nobody’s idea of frictionless trade.

If it’s any consolation, shrinking size while maintaining price is a common practice among food products across the board. It even has a name—“shrinkflation”—and it can affect everything from coffee (bags switching from 16 oz to 12 oz) to laundry detergent sizes to tea—a box that once contained 20 bags will remain the same size and price but now holds just 12 bags. It’s a simple way to boost profits without boosting prices.