It's a double dilemma for many people: The cost of college is rising and may not be affordable. But in a tight job market, it's tough to get a decent-paying job without a bachelor's degree.

Or is it?

A new study from Georgetown University identifies 29 million jobs in the United States that require some measure of education and training past high school, but not a four-year college degree. The study refers to these jobs as "middle jobs." They make up more than one in five jobs overall, and almost half of all jobs that pay at least $35,000 a year.

And some of these jobs pay a lot more than that. Nearly 40% of middle jobs pay more than $50,000 a year -- including 14% that pay more than $75,000.

So, what kinds of jobs are we talking about, and exactly how much education is required?

Nearly half of middle jobs involve working in an office, with positions ranging from technical support to sales to managerial. Another third of the jobs are blue-collar. About 10% of middle jobs are in the health care field, including more than 1 million registered nurses.

As far as education and training, requirements range from apprenticeships to industry-based certificates to two-year associate's degrees. Most middle jobs require some on-the-job training, from three months to a year or more. Three of out of five require at least one year of related work experience.