In the 1760s, Mathurin Roze de Chantoiseau opened a series of Parisian shops that boasted a curative consommé. Although the main draw was the broth, Roze’s establishments also set a new standard for dining out, with individual tables, service throughout the day, and nice dishware. In her history of dining, Rebecca Spang credits Roze with inventing the modern restaurant.

Today, enterprising restaurateurs can skip the medicinal broth and head straight for the hard data. Economists, psychologists, and marketing professors alike have generated reams of instructive research about restaurants. Take visual cues that influence what we eat: A 2012 study on plate size and color reported, among other things, that diners served themselves about 20 percent more pasta when their plates matched their food [1]. Researchers in France found that when a dark-colored cake was served on a black plate rather than a white one, patrons perceived it as sweeter and more intense [2]. Lighting matters, too. When Berlin restaurant patrons ate in darkness, they couldn’t tell how much they’d had: those given extra-large portions ate more than everyone else, but were none the wiser—they didn’t feel fuller, and they were just as ready for dessert [3]. Time is money, but that principle means different things for different types of restaurants. Unlike fast-food and all-you-can-eat places, fine-dining establishments prefer customers who linger and spend. One way to encourage patrons to stay and order that extra round: put on some Mozart. British researchers found that when classical, rather than pop, music was playing, diners spent more [4]. Another study found that fast music hurried diners out [5]. Particular scents also have an effect: diners who got a whiff of lavender stayed longer and spent more than those who smelled lemon, or no scent [6].Meanwhile, things that you might expect to discourage spending—“bad” tables, crowding, high prices—don’t necessarily. A study out of Cornell’s School of Hotel Administration tracked 1,400 meals at a Chevys restaurant, to see which tables had the highest SPM—spending per minute. Diners at banquettes stayed the longest, but didn’t spend much more than those at other tables, so those tables had the lowest SPM. Diners at bad tables—next to the kitchen door, say—spent nearly as much as others but soon fled. The authors concluded that restaurateurs need not “be overly concerned about ‘bad’ tables,” given that they’re profitable [7]. As for crowds, a Hong Kong study found that they enhanced a restaurant’s reputation, suggesting great food at fair prices [8]. And doubling a buffet’s price led patrons to say that its pizza was 11 percent tastier [9]. When the check comes, diners can be downright capricious. One researcher who studies tipping found that if servers had blond hair [10] or crouched next to customers [11] while taking orders, they got bigger tips. Finally, when female servers drew a smiley face on bills, tips increased by about 20 percent—leaving everyone happy [12].