Are some people just born entrepreneurs, or can anyone learn the ropes? The debate goes both ways, but it’s clear that successful entrepreneurs share many characteristics, however they acquired them.

Chief among them is the willingness to take risks, say experts and entrepreneurs themselves. Just launching a business is a big risk, of course, but taking risks routinely and being willing to live by the consequences is a mindset for the successful entrepreneur.

It’s not just any risk, though. “A good entrepreneur takes a carefully calculated risk. If the pluses outweigh the minuses, only then do they take the shot,” says Dave Ratner, president of Dave’s Soda & Pet City of Springfield, Mass.

That’s just what Ratner did last fall when he added a third business to his line of existing enterprises. Ratner’s new venture, Logo Goes Here, provide network-quality advertising for pet stores.

It’s a new field for him, but because of knowledge gained in his current pet shop operations, Ratner saw a void in the market. He weighed his chances carefully, then decided, “There’s a need for this. I have a solution to their advertising problem.”

Such willingness to risk everything is often fueled by the burning desire to achieve. “The people who are most successful are hungry,” notes Jeffrey Mayer, author of Success Is a Journey: 7 Steps to Achieving Success in the Business Life (McGraw-Hill Trade, 1998) and founder of a Web site aimed at entrepreneurs, www.SucceedingInBusiness.com.

Often those most hungry are first and second generation Americans, people like Tom Antion. “When immigrants come over, they have to scratch for any income at all,” he explains. “For their kids, taking the risk on your own shoulders for the greater reward is attractive.”

Antion’s father worked as an electrical contractor after immigrating to the United States from Syria, so young Tom absorbed the entrepreneurial spirit early on. He owned five apartment complexes and a hotel before graduating from college.

Later, he owned a nightclub, then an entertainment company. Today he owns Tom Antion and Associates Communication Co., where he’s a consultant on Internet marketing for small businesses.

When the going gets tough—and it will soon enough—it’s that driving hunger to succeed that makes the successful entrepreneur stick it out after others quit. As Antion declares, “I am totally unstoppable.”