Section Five
D e m o g r a p h i c s
Livingston Union School District | Facilities Master Plan
&
C a p a c i t y
Step Two: Birth Rates and Migration Factors
Migration Rate
A Cohort Survival Model (CSM) is used to determine the historical migration
rate of students as they progress from Kindergarten through eighth grade. The
CSM relies on historical enrollment data to capture the effects of all the factors
impacting student enrollment over the years. It projects future enrollment based
upon past trends of students progressed at each grade level.
Figure 9 shows the changes in the cohort over time as the current size of the cohort is shown at each grade level along with the size of the cohort when it was in Kindergarten. If the blue bars are extended above the blue trend line this represents that the cohort for that year has grown since Kindergarten, consequently if the blue
bars are below the trend line, the cohort has declined.
FIGURE 9: COHORT CHANGES SINCE KINDERGARTEN 2015/16
The CSM projection calculates the enrollment for Kindergarten using the Birth
Capture Rates as described. The enrollment for each grade first through eighth is
equal to the preceding grade’s enrollment from the previous year plus (or minus)
a “Cohort Change Factor” (CCF). For example, seventh grade enrollment in 2013
is equal to the sixth grade enrollment in 2012 plus (or minus) a CCF. The CCF for
each grade is an average of the historical changes in enrollment from year to
year for that particular grade. These average historic CCFs reflect the impact of
variables that influence a district’s enrollment.
This Study uses a migration rate that considers the last three years of historical
changes in enrollment. Table 4 shows the historical migrations by grade level
and the resulting three year migration rates. Note that the migration rate calculations exclude the TK students as they are not eligible to migrate to 1st grade.
TABLE 4: MIGRATION RATES BY GRADE
Year
From>To
2005>2006
2006>2007
2007>2008
2008>2009
2009>2010
2010>2011
2011>2012
2012>2013
2013>2014
2014>2015
3-Year
Migration
K>1* 1>2
13
15
19
-3
-5
-8
-10
1
4
5
-18
-3
-5
3
-11
7
8
16
9
-18
5.3
-2.5
Grade From>To
2>3 3>4 4>5 5>6
10
-1
-1
11
2
-3
5
0
-7
-22
5
5
3
-10
-8
-6
-11
-5
4
3
-3
-6
3
-2
-4
-17
7
0
-13
-11
12
4
-12
13
3
-4
-10
-2
-17
0
6>7
1
-3
2
1
5
8
5
2
2
8
7>8
-7
14
-4
3
-6
10
10
4
5
0
-11.2
5.0
2.3
1.5
-5.5
-0.7
70