In economics, "inferior goods" are goods that consumers buy less of as their incomes rise, instead opting for more desirable alternatives. For example, many college students swear they will never buy mac and cheese, or ramen noodles, ever again once they have their first "real" job. For them, macaroni and cheese, and ramen, are inferior goods. They plan to buy less as their incomes grow.
As incomes fall, the opposite happens: inferior goods begin to look more appealing than they did during times of higher income. For example, soup has often been identified as a product that does well during poor economic times. (And during good economic times, the marketing folks at Campbell soup have needed to work extra hard to remind us to buy their red and white cans: you may remember the "Soup is good food" campaign from headier economic times.)
Well, evidence is growing that fast food, and even trips to the movie theater, may be the new inferior goods. Even though they are hardly "necessities," and not that long ago were considered a bit of a treat, it seems that American consumers are turning to them as they become more concerned about their current and future income prospects. And it is certainly possible that "getting by on less" nowadays means eating at Burger King instead of Applebee's.