Thanks to labor unions, wages have improved, the workweek is shorter and the workplace is safer.

However, employers sometimes complain that unions are harmful to business and to the economy. From an employee standpoint, is being a union member beneficial? Here are some pros and cons of union jobs.

The Pros of Belonging to a Union

Better wages. The median weekly income of full-time wage and salary workers who were union members in 2010 was $917, according to the U.S. Bureau of Labor Statistics. For nonunion workers, it was $717.

More access to benefits. Some 93% of unionized workers were entitled to medical benefits compared to 69% of their nonunion peers, according to the National Compensation Survey published last year by the U.S. Bureau of Labor Statistics. The survey represented about 101 million private industry workers and 19 million state and local government employees.

Unmarried domestic partners -- same sex and opposite sex -- also had access more often to these benefits if they were unionized. Workers with union representation also had 89% of their health insurance premiums paid by their employer for single coverage and 82% for family coverage. For nonunion workers, the comparable numbers were 79% and 66%, according to the Bureau of Labor Statistics. And 93% of unionized workers have access to retirement benefits through employers compared to 64% of their nonunion counterparts.

Job security. Nonunion employees are typically hired "at will," meaning they can be fired for no reason. There are exceptions. Employers can't terminate a worker for discriminatory reasons such as race, religion, age and the like. Nor can they fire an at-will employee for being a whistleblower and certain other reasons.

However, workers with union jobs can only be terminated for "just cause," and the misconduct must be serious enough to merit such action. Before an employee can actually be fired, he or she can go through a grievance procedure, and if necessary, arbitration.

"If I know I can't be easily fired, I can speak up more freely," says Monica Bielski Boris, assistant professor of labor and employment relations at the University of Illinois.

Strength in numbers. Unionized workers have more power as a cohesive group than by acting individually. "What you gain is the muscle of collective action," says Hoyt Wheeler, a professor emeritus at the University of South Carolina who is now a labor arbitrator. Through collective bargaining, workers negotiate wages, health and safety issues, benefits, and working conditions with management via their union.

Seniority. Rules differ among collective bargaining agreements, but in the event of layoffs, employers usually are required to dismiss the most recent hires first and those with the most seniority last -- sometimes called "last hired, first fired."

In some cases, a worker with a union job who has more seniority may receive preference for an open job. Seniority also can be a factor in determining who gets a promotion. The idea is that seniority eliminates favoritism in the workplace.

"The chief advantage of seniority is it is objective," Wheeler says.

The Drawbacks of a Union Work Life

Union dues and initiation fees. Dues can range from $200 to several hundred dollars per year, partially offsetting higher wages. Some unions also require a one-time initiation fee. Dues help the union pay for officials' salaries and conducting union business, but members sometimes complain about the amount they pay, how the money is spent, and how it is allocated between the national and local union.

Loss of autonomy. The flip side of job security is that union members sacrifice individuality by belonging to a group. You may disagree with the union's decisions, but you are bound by them.

"It's a trade-off," Bielski Boris says.

Less collaborative work environment. Unionized workers experience less of a sense of partnership and trust with their supervisors, according to a survey conducted by the Gallup and Healthways organizations last year.

More than 149,500 interviews of workers were conducted. Regardless of whether they worked in local, state or federal government or outside of government, unionized employees more often said their supervisor treated them like he or she was their boss and not a partner than did their nonunion counterparts. Among nongovernment employees, for example, the margin was 48% to 36%.

Similarly, nonunion employees across the board said their supervisor created an environment that is trusting and open more often than those who were unionized. Among nongovernment workers, the margin was 80% to 71%. Despite this, there aren't large differences in job satisfaction between the two groups, according to Gallup and Healthways.

Employers' relationships with unions have become more acrimonious since the 1970s, Bielski Boris says. And nowadays, some governors of revenue-starved states are blaming public sector unions for their woes and aggressively attempting to reduce benefits and curtail collective bargaining rights. (Public sector unions account for more than half of all union members in the United States.)

"The political climate can often turn against unions and their members," Bielski Boris says. The political attacks, combined with declining membership rolls, could weaken gains made by unionized employees.

Seniority. The advantages that seniority provides can be a detriment to newer employees. You may be more productive or talented than a veteran worker, yet you're the one who likely will be laid off in a downsizing. A union's collective bargaining agreement also may require employers to provide other perks based on seniority rather than merit to the detriment of junior workers with union jobs. Some agreements enable a worker displaced from a job to "bump" another worker with less seniority and take his or her job.

Wheeler, the labor arbitrator, understands the pros and cons of being a union member better than most. "On balance, I think workers are better off with a union than without one, by far," he says.