Here is an interesting study that questions whether remedial math classes at two-year colleges have any statistical help towards achieving a two-year degree.
The issue investigated is not really relevant to most of my students. Those researches compared students who took remedial classes with students who went directly into "college algebra". Most of my students are in the process of earning degrees or certificates that only require basic math (Math 20 and/or Math 25) and do not take algebra.
(I also question whether local employers would want a college to give a degree to a student able to do algebra but not work fluently with percents, proportions, and measurement unit conversion.)