There doesn't seem to be much research out there (yet) about the relationship between the decrease in vocational education participation and the increase in alternative programs and Area Learning Centers (ALCs) in Minnesota and other states with similar alternative learning programs. However, we can definitely look at the numbers and discuss conclusions that can be drawn from the facts.
158,289 students attended alternative education programs including 252 ALCs, 18 contract alternatives, 54 alternative programs and 232 targeted services programs in 2009 according to the Minnesota Department of Education. The graph attached in the file below shows the increase in the number of students enrolled in alternative programs since the late 1980s.
The data for ALC enrollment shows a 32% increase in enrollment in ALCs over the last decade – 2000-2009.
In comparison, the National Center for Education Statistics (NCES) most recent data on secondary student participation in vocational education (now called Career/Technical Education or CTE) shows some decrease in CTE participation amongst public high school graduates over the same period which can also be found in the attached file.