For an increasing number of students at American universities, Old is suddenly in. The reason is obvious: the graying of America means jobs. Coupled with the aging of the baby-boom (生育高峰) generation, a longer life span means that the nation’s elderly population is bound to expand significantly over the next 40 years. By 2040, 25 percent of all Americans will be older than 65, up from 14 percent in 1995. The change poses profound questions for government and society, of course. But it also creates career opportunities in medicine and health professions, and in law and business as well. "In addition to the doctors, we’re going to need more sociologists, biologists, planners and specialized lawyers," says Professor Edward Schneider of the University of Southern California’s (USC) School of Gerontology (老年学). Lawyers can specialize in "elder law", which covers everything from trusts and estates to nursing-home abuse and age discrimination (岐视). Businessmen see huge opportunities in the elder market because the baby boomers, 74 million strong, are likely to be the wealthiest group of retirees in human history. "Any student who combines an expert knowledge in gerontology with, say, an MBA or law degree, will have a license to print money," one professor says. Margarite Santos is a 21-year-old senior at USC. She began college as a biology major but found she was "really bored with bacteria." So she took a class in gerontology and discovered that she liked it. She says, "I did volunteer work in retirement homes and it was very satisfying."

Who can make big money in the new century according to the passage