... measurement may become more difficult:

When research in 2011 showed that workers in the fields of science, technology, engineering, and mathematics earned a premium of 25 percent over other workers and have just a 5.5-percent unemployment rate, it reinforced strong economic incentives to get more people into those STEM fields.

But research like that might soon become more difficult to conduct. That’s because the U.S. Census Bureau wants to stop asking people in a key national survey about their field of study.

Since 2009 the bureau has collected data on people’s undergraduate fields of study as part of its American Community Survey, at the urging of the National Academy of Sciences and the National Science Foundation. The survey, which is based on responses from more than three million households, is used to collect demographic information and keep track of trends between the decennial censuses.

On this blog, we’ve previously written about how underemployment hit recent graduates and that ever-present question: “Is your college degree still worth it?” Without the field-of-study data from the American Community Survey, that research would have been nearly impossible to compile. ...

The division chief of the American Community Survey Office, Jim Treat, says a cost-benefit analysis was used to make the recommendation that the question be dropped. In an email to The Chronicle, Mr. Treat wrote that his office had looked at the perceived burden of including each question and had surveyed federal agencies to see which data were used.

If the Census Bureau were to drop the question, Mr. Gawalt said, it would not be impossible for the NSF to run its own survey again, but doing so wouldn’t be cheap. Before the Census added the field-of-degree question, he said, the NSF spent an estimated $17-million to compile the information, and the data had less detail than the American Community Survey provides. The NSF’s elimination of its survey resulted in savings of $4-million every other year.