If you want to know what economic policy would look like in a Hillary Clinton administration, you can read her speeches or policy positions or look at the backgrounds of the advisers she surrounds herself with.

But it’s also worth examining a 21-page briefing paper issued on Oct. 25 by Obama White House economists about an important concept with a forbidding name: labor market monopsony. The paper is a prime example of the direction left-of-center economic policy is going, evident not just in the Obama administration’s second-term priorities but in a range of work at liberal think tanks and in Mrs. Clinton’s own economic proposals.

Labor market monopsony is the idea that when there isn’t enough competition among businesses, it is bad news for workers. When an industry includes only a few big companies, they don’t have to compete with one another as hard to attract employees — and so end up paying their workers less than they would if there were true competition. It’s the flip side of how monopoly power lets companies charge higher prices to consumers.

It’s an idea that has a long lineage in economic thought but has been barely discussed in mainstream policy-making circles until recently. Every year since 1947, White House economists have issued the “Economic Report of the President,” describing in great detail the United States’ strengths and challenges. The phrase “labor market monopsony” appears not once in tens of thousands of pages.