Saturday, June 6, 2009

Bursting the Bubble?

A wise man once said that it's a good exercise to look backwards once in awhile and see where you've been. Kinda makes you take stock of how you got to where you are. We were so interested in the numbers that were presented at Thursday's Diversity meeting that we couldn't resist takin' 'em back and playing with 'em a bit.

The Sun Prairie Area School District relies heavily on projections made by the the University of Wisconsin's Applied Population Lab (UW-APL). Projections are great, but they are exactly that....projections. At some point, coming up with these numbers has to involve what some scientists refer to as the "WAG Technique" in Wild Ass Guess. Of course, any projection is based on assumptions, and as long as those assumptions ring true, the projections can be fairly valid.
So let's take a trip down memory lane....

The District's Strategic Plan of 2004 (fueled by UW-APL 2003 data)
The APL projections for 2008-09 made 5 years earlier were eerily accurate. In 2003, the APL projected 2972 [K-5] elementary students (actual was 2924); 1401 [6-7-8] Middle School students (actual = 1372); and 1807 [9-12] High School students (actual = 1807). Remember, though, that 71 high school students are situated in the Alternate Learning Center. That means only 1635 are actually in the high school.

Unfortunately, that's about where accuracy gets off the bus. The 5-year projection for High School enrollment (Gr 9-12) beyond 2008-09 was for 2288 students. To reach that level of enrollment, we'd have to experience sustained growth of 5% enrollment increases over each of the next 5 years.

The total district enrollment projection for 2012 (3 years from now) was 7604 students. And that was before adding in the 4K, which wasn't part of the plan back then. Our 2009 K-12 enrollment was 6103. That would mean an increase of 500 students per year to reach that projection.

It would seem that the economy and the bursting of the housing bubble may have been nature's way of putting its foot on the growth brake. Yet another reason to view projections with caution. Projections do NOT (CANNOT) consider the effects of things like 100-year flooding, major economic collapses, or unprecedented state budget shortfalls.

Where does our growth come from?
General consensus is that most of our enrollment growth comes from births. That's why Phil Frei focuses heavily on kindergarten enrollment numbers. It makes a lot of sense, particularly when you consider the high school. Kids don't get born at age 14-18. So the only way we increase high school grade level enrollment is through a net INFLUX into the district. To reach the kind of growth they projected in 2004, we'd have to add 25-30 kids at EACH grade level for each of the next five years. That would mean a LOT of families moving into the district with high school age students, and NONE moving OUT of the district.

Another way to look at projections is to view them in terms of class size. This year, district wide, we AVERAGED about 470 kids per grade level, with a low of 430 (grade 11...hmmmm) and a high of 512 grade 2). Remember we built the new 10-12 high school with a capacity of 2000 students. Divide 2000 by 3 grade levels and you get 667 students per grade. That represents a whopping 42% increase over the average grade enrollment today. THAT is why most of the community felt that ONE high school was plenty.

October 2006 APL projections
During the first referendum attempt for the high school, APL was called upon again. These 2-year projections for 2008-09 were 1718 (high school) 1412 (middle school) and 3059 (elementary). Again, you see the focus for long-term enrollment growth is on the elementary school aged kids.

Their projections for 8 years from now (2016-17) were 2722 in grades 9-12 (680 per grade); 1927 for grades 6-8 (642 per grade); and 3499 for grades K-5 (583 per grade). Seems inverted, doesn't it? Those projections would suggest that growth is declining from that point on. This suggests that the growth "bubble" is really at this year's 4th graders, with class size (growth) tailing off steadily from that point.

Referendum Flyer November 2007
This infomercial scared the beejeezus out of people with projections of 2700 High School (9-12, we hope) students within 8 years of now (2017). Do the math folks, that translates to a graduating class size of 700 students. Hell we haven't even hot 500 yet, and the closest we get by juts advancing forward our current students is 512 based on this year's 2nd graders. For reference, this year's grade 12 is 467 (just about average) while next year's falls to 430.

Projecting it forward
We'll catch grief for this, but a simplistic (yes, perhaps overly so) projection can be made by using a simple technique of "projecting forward" current grade levels to see how things play out. Is it exact. No way. What it does not consider is births (or call them future kindergartners), although we've read that birth rates have declined significantly in recent years. This "projecting it forward". It just looks at current students. It assumes (quite simply) that a net zero students either enter or leave the district. That being said, you can do the math on how much net 'growth" would be required to reach enrollment of any particular level.

A few Words on Grade Progression Ratios
The APL calculates what it terms "grade projection ratios" which essentially represent projected changes in grade level enrollment from year to year. One last little mystery to solve. Astute observers will note a sudden increase in enroillment at Grade 9 (1.18, or 18% over 8th grade). This actually represents students coming into the public school from private or parochial schools, such as Sacred Hearts, which only gextends through 8th grade. You might also note a DECREASE at grades 10 and 11. Does this decrease relate to dropouts? We're not sure, but like many other things, the district doesn't offer any commentary on these little questions.

Take a look at the two graphs below. They are scaled identically. The first is OUR simplistic projection by simply advancing grade level enrollments forward. The second is the projection from the APL associated with the November 2007 referendum information. Both plots are ONLY fro the "new" high school, i.e., grades 10-12. Note the much steeper growth projected by the APL. That was before the economy and housing market hit the skids. Remember...the school was built to hold 2000. The bubble seems to appear at grade 2 enrollment. After that, has the bubble been burst? Will we face declining enrollment?