Glenn Sharfman:

We all want more young people to attend college. Who would argue with that? Politicians and educators at all levels extol the obvious virtues, from enhanced earning potential to a greater satisfaction in life. One increasingly popular way to encourage college attendance is through dual enrollment, in which students take courses in high school for both high school and college credit.
In theory, dual enrollment enables high school students to accrue college credits for very little cost and imbues them with a sense of confidence that they can complete college work. If students can succeed in college classes while still in high school, conventional wisdom holds, they will be more likely to matriculate at the postsecondary level.
In Indiana, dual enrollment is encouraged at the highest levels, with state Education Secretary Tony Bennett maintaining that at least 25 percent of high school graduates should pass at least one Advanced Placement exam or International Baccalaureate exam, or earn at least three semester hours of college credit during high school.
In reality, though, dual enrollment may do more harm than good.

Related: Credit for non-Madison School District Courses.