Jon James:

The economic returns to education are well documented. It is also well-known that college graduates with certain majors will earn more than others and find it easier to land a job. But surprisingly, the courses students take in high school also make a difference, when the courses are mathematics. Even among workers with the same level of education, those with more math have higher wages on average and are less likely to be unemployed. These findings suggest that even students ending their formal education after high school can increase their future earnings by investing in more math courses while in high school.

High school graduates earn more money in general than high school dropouts. This well-known fact is a powerful incentive to finish high school. But is it just the diploma that counts, or do the particular courses students take while in high school matter for their future job prospects? Students can opt for a variety of courses, from vocational tracks to advanced placement classes for college credit, during their final four years of required education.
Most high school graduates choose a curriculum that is far more rigorous than the minimum requirements. This is most evident in mathematics courses. For example, in 2009, 75 percent of high school graduates completed math coursework at the level of Algebra II or above. Most of these students could have stopped at Algebra I and satisfied the minimum high school requirements. Only six states required Algebra II for graduation as of 2006. About 11 required Algebra I, six required geometry, and the remaining 27 required only that students complete a minimum of three years of mathematics at any level.
The fact that so many students take a rigorous math curriculum is not surprising given that a minimum of Algebra II is necessary for adequate college preparation. But an analysis of detailed high school transcript data and employment outcomes suggests that a more rigorous high school math curriculum benefits even those who do not go to college. While math may be difficult for many, our findings indicate that the payoffs for all students may be substantial.

Unsurprising, particularly when one encounters young people unable to comprehend cell phone costs, student loan terms or simply make change.
Related: Math Forum audio / video and Connected Math.