A recent study detailed in the Harvard Business Review says workers who graduated from elite colleges perform better than those who did not, but only by a little, even as they tend to cost companies more.

The researchers tracked the performance of 28,339 students from 294 universities in 79 countries. The schools themselves varied from Top 10 to Top 20,000 as measured by Webometrics global university rankings. The participants spent two months working in virtual teams on real-life business consulting projects for corporate clients. The researchers tracked the quality of their output as well as a range of hard and soft skills such as cooperation with team members, leadership, language proficiency, technical skills, emotional intelligence and creativity.

Once they controlled for age, gender and year of study, they found that those from higher-ranked universities performed about 1.9 percent better for every 1,000 positions in the rankings: that is, someone from an elite university performed 1.9 percent better than those in the top 1,000 schools, performed 3.8 percent better than those in the next 1,000 schools down, 5.7 percent better than those in the next 1,000 schools down and so on. At 10,000 positions down, the different is 19 percent. While 19 percent is dramatic, the researchers noted that most companies will be selecting people from within a much narrower band of educational attainment. In the case of universities whose rankings are just a couple hundred positions apart, the difference is believed to be closer to just 1 percent.

The reasons are predictable: Top universities have a broader pool of student applicants to draw from, and they can pay their instructors more and so have higher quality training. One thing that was not a factor was institutional environment. Graduates from lower-ranked universities showed an equal level of motivation and work ethics, so this could be more affected by personality and other individual factors.

While the performance differential is narrow, the pay differential is not: the researchers pointed to other data showing that the average early career salaries of graduates from the top 10 colleges ($72,160) in the United States are 47 percent higher than those with degrees from the 10 colleges within the City University New York (CUNY) school system ($48,960), many of which are ranked within the top 100. It would appear, then, that hiring managers are paying a premium for only a slight bump in effectiveness.