With the national unemployment rate climbing to a five-year high of 6.1 percent, more than 600,000 fewer jobs in the workforce today than at the beginning of the year, and job security becoming more uncertain, some people are thinking about going into business for themselves ­ particularly those who recently lost their jobs.

But now may not be the best time, according to ClearRock, an executive coaching and outplacement firm headquartered in Boston.

To be sure, starting a business is not for everyone ­ especially if your prime motivation is because you have no other way of earning a living, ClearRock says. Although more than 12 percent of the labor force engages in some new entrepreneurial activity annually, only just one in 10 people started a business because they had no other choice for work, reports the Global Entrepreneurship Monitor of U.S. entrepreneurial activity.

“Most people who become self-employed are motivated by the possible benefits of starting a business, and not because they weren’t able to find other work,” said Annie Stevens, managing partner with ClearRock. “Successful entrepreneurs are people who choose entrepreneurship even when they have good prospects for other employment.”

In addition, about one-third of small businesses fail to make it past the second year, and only about 40 percent are still in existence after four years, according to the U.S. Bureau of Labor Statistics.

Regardless of whether people who are unemployed start a business because it was the only suitable alternative ­ or as the result of a deep desire or interest ­ they need to ask themselves the following questions before launching a business venture, according to ClearRock:

Are you suited for self-employment?  “People who start businesses must be prepared to make personal and financial sacrifices,” says Greg Gostanian, managing partner for ClearRock.  “But those who are unemployed, or have recently been unemployed, must also be certain they have sufficiently recovered emotionally from losing a job before launching a business.”