5 middle-class careers that are growing, and 5 that are shrinking

The U.S. economy is forecast to add more than 7 million jobs over the next five years, but whether workers benefit from that growth depends on which sector they work in.

Middle-income earners are most at risk for losing out in the economy, given that jobs paying middle-class wages are projected to grow by only 3 percent, according to a new study from CareerBuilder. High-wage and low-wage jobs, meanwhile, will grow by 5 percent through 2021. Even worse, 61 percent of the 173 occupations that are projected to lose jobs are within the middle-wage category, the research found.

That impact is already being felt by many Americans, given the labor dynamics of the post-recession years. College graduates are benefiting most during the recovery, grabbing the largest share of the nearly 12 million jobs that have been created following the downturn, while less educated Americans are finding themselves pushed into lower-paying, lower-skilled jobs.

Those trends are underlying much of the anger expressed by voters in the run-up to the presidential election, with GOP candidate Donald Trump vowing to "make America great again" by reclaiming manufacturing jobs, among other issues.

"The economy has taken a lot of jobs way from the middle-wage sector," said Michael Erwin, senior career advisor at CareerBuilder. That is "either pushing them into unemployment or into low-skill minimum-wage jobs."

That trend isn't only a problem for those workers, but also for the economy as a whole, given that lower earnings or higher unemployment leads to lower consumer spending and can impact every sector, from housing to automobiles. CareerBuilder views middle-wage jobs as those that pay $13.84 to $21.13 per hour, or about $29,000 to $44,000 annually.

Workers in middle-wage occupations that are projected to shrink within the next five years should consider how to retool and prepare for a career switch, Erwin said. That can range from reframing a skill -- such as emphasizing the communication tools one has learned on the job -- to going back to school.

Read on to learn about the five middle-wage jobs that are projected to both grow the most and lose the most jobs within the next five years.

5. Growth: Office clerks, 4 percent

Office clerks are projected to be the fifth-fastest growing middle-wage profession in the next five years. More than 128,000 jobs will be added by 2021, bringing the number of office clerks to 3.49 million.

Office clerks earn an average of about $30,000 annually, according to the Bureau of Labor Statistics. The job requires a high school diploma, and tasks range from filing records to answering calls.

4. Growth: Tractor-trailer truck drivers, 4 percent

There's strong demand for heavy and tractor-trailer truck drivers, and not enough workers to fill the jobs, according to CareerBuilder. The American Trucking Associations has pegged the shortage at 30,000 qualified drivers, which is why the industry is reaching out to underrepresented groups such as women to fill the gap.

Benefits of the job include flexible hours and the opportunity to be your own boss. The job pays about $40,000 annually, according to the BLS.

Jobs in this profession should grow by 4 percent by 2021, reaching just over 2 million workers.

3. Growth: Maintenance and Repair Workers, 5 percent

Maintenance and repair workers are in demand because it's the type of job that can't easily be replaced by automation. This career doesn't require a college degree, and it pays about $36,000 per year, according to the BLS.

The occupation should grow by 5 percent over the next five years, reaching 1.5 million workers, CareerBuilder found.

2. Growth: Customer service representatives, 6 percent

Online commerce is only growing, and that means more demand for customer service representatives. If unhappy customers have a problem, an automated service isn't likely to cut it, which means continued demand for this occupation.

Workers in this field make about $32,000 annually, according to the BLS. CareerBuilder expects that corporations will hire about 172,000 additional customer reps over the next five years, bringing the total to 2.8 million Americans in the job.

1. Growth: Medical assistants, 11 percent

Thanks to the aging of America, health care-related occupations are projected to grow in the next several years, with medical assistants at the top of the list for middle-wage careers.

Medical assistants require a postsecondary non-degree credetial, such as a certificate, and work in health-care offices such as doctors' practices and hospitals. The median pay is about $31,000 per year. CareerBuilder projects about 69,000 new jobs in this field by 2021, bringing the total to about 701,000.

5. Declining: Bookkeepers, -2 percent

Jobs for bookkeeping, accounting and auditing clerks are due to shrink by 2 percent over the next five years, shedding almost 28,000 jobs, according to CareerBuilder. The main culprit is software and online programs, which is allowing many businesses to automate these functions.

This career pays about $37,000 annually, which means thousands of middle-income Americans working in this field may be shifting into new roles or retiring by 2021.

4: Declining: Carpenters, -2 percent

Carpenters may be in demand, but the issue here is that not enough young Americans are learning the trade, which is leading to a projection of less employment, Erwin said.

That said, carpentry is a solid middle-class profession that pays about $42,000 per year, according to the BLS.

3. Declining: Travel agents, -6 percent

Blame the internet for the decline of the travel agent. With sites such as Expedia and Priceline taking market share, that's putting some travel agents out of business.

The profession will lose about 5,000 jobs over the next five years, declining to a total of about 73,000 workers. Travel agents make about $36,000 annually, according to the BLS.

2. Declining: Farmers and ranchers, -7 percent

Technology is making farming more efficient, but that means declining demand for humans on the farm. The number of farmers, ranchers and other agricultural managers will decline by 7 percent to about 459,000 workers in 2021.

This occupation pays about $64,000 annually, according to the BLS.

1. Declining: Printing press operators, -9 percent

With fewer Americans reading traditional newspapers, this middle-tier job is losing steam. This occupation will shed about 15,000 jobs over the next five years, a decline of 9 percent.

Printing press operators earn about $37,000 annually, according to the BLS.