A homegrown, rapidly expanding American invention is a cost-effective tool for increasing post-secondary educational attainment and gainful employment. It is the quickest education and job training award offered by American higher education, and has the capacity to raise the country’s global educational standing.

The object of these accolades: certificates awarded for finishing a job training course. The well-regarded Center on Education and the Workforce at Georgetown University, the source of this praise, notes that very few studies or reports have focused on this education/training option.

Over one million certificates were awarded in 2010, up from 300,000 in 1994. These certificates have grown from 6 percent of post-secondary awards in 1980 to 22 percent. Community colleges grant a little over half of these certificates, and private for-profit institutions award 44 percent.

The course-work to earn these certificates, primarily concentrating on job skills in a particular sector or industry, can take about two years to complete (“long-term training”), although more than half take less than one year (“short-term training”). A key point, though, is that these certificates are academic credentials for course completion. They are not certifications of competency in a particular skill such as Cisco’s validation of skills needed to perform network jobs.

While acknowledging that feature, there is no denying that these job training courses are fulfilling a popular demand. Particularly after the harsh recession of 2008-09, workers are afraid of losing their jobs and want to take training courses to improve their skills. They hope that this additional training will increase their value to their employers or in a worse case prepare them for another job.

These certificates are earned by persons with varying degrees of education and training: those with no education or training after high school, those with some post-secondary education, and those with an associate’s or bachelor’s degree. Two out of every three workers who have a certificate and a college degree earned the certificate first, an indication that certificates can serve as a stepping stone on the way to a college degree, according to the Georgetown center. The idea that one needs only an academic degree or a vocational certificate is changing into the concept that one may need both.

This brings us to the issue of whether these certificates are effective. Have they helped to prepare people for jobs demanding higher skill levels or for different types of jobs than workers may have had before?

Despite the popularity of these certificates, the answer — unfortunately — is not entirely clear.

On average, certificate holders earn 20% more than high school-educated workers. Many certificate holders earn more than workers with associate’s degrees and some earn more than workers with bachelor’s degrees, according to the Georgetown center. These conclusions, though, should be treated cautiously since national studies are few and some state and institutional studies have contradictory findings.

Comparing short-term training to long-term training, less positive gains are seen. Some research on short-term programs has shown no success in obtaining jobs or in achieving higher salaries, while other studies show some gains but not as significant as for persons who took long-term training. These findings about limited or no gains from short-term training are especially troublesome since more than half of certificates awarded are for short-term training. This, too, is an area that needs more analysis.

A common thread throughout these studies is that the choice of job area in which to receive training is crucial. It makes no sense to train for areas of the economy where there are few jobs. For those who take short-term job training, it is even more important to make the right decision about job availability since the effectiveness of that training is most in doubt. The positive side is that some job areas are more appropriate for short-term training than others, such as police and protective services, especially for men, and business and office management, especially for women.

An additional point is that any training should be viewed as one component in a long range career plan to prepare for good jobs and decent wages. One should ask — is this course a building block for further education or training? If courses are taken at random without any consideration of whether they build on one another, much money and time can be wasted.

In sum, certificates for job training are very popular, despite the need for more research on their effects. What is known is that to improve one’s chances for a job and for higher pay, longer-term job training is generally more productive than short-term training. In addition, an applicant should know whether there are jobs available for the skills that are being taught. Lastly, any training should fit within a long-range career plan to improve one’s skills and level of education.

Job training certificates show a strength of American society: we are willing to experiment to find the best way to do something. But, a caution is that we must balance this innovation with systematic ways to inform those interested in such training about realistic job prospects and about the value of long-range career planning.

Boldness needs to be matched with prudence.

Certificates: Gateway to Gainful Employment and College Degrees, Anthony P.Carnevale, Stephen J. Rose, Andrew R. Hanson, Center on Education and the Workforce, Georgetown University, Washington, D.C. June 2012.

This article written by Jack Jennings first appeared as a blog in the Huffington Post on August 3, 2016.