Estimating Supply & Demand in PK4 Planning

As I have described earlier (here, and here), I am working on projection estimates for PK4 in MNPS. Given the limitations of a summer-only role and the many, many factors at play in the decisions, I do not know what role these estimates will ultimately play in the strategy around PK4 expansion. But I can at least feel confident that I am providing accurate and useful information around specific questions, namely: the (1) available supply and the (2) current unmet need for PK4 across the district and in each cluster, and (3) illustrate trends in each cluster’s distinct PK4 needs and assets. So! In the interest of sharing what I have learned thus far, here is a progress report of sorts.

Definitions:    I have already sought and obtained initial figures on each of these inputs, and am in the process of cleaning, re-organizing, and crunching the numbers so that I can pull them together in a meaningful way. 

1.     Demand = Number of students who applied for this year’s PK4 through MNPS, as organized by their zone of residence

2.     Need = Students who are projected to enroll in a MNPS zoned school for Kindergarten the following year (Proxy for PK4)

3.     Need Trend = Anticipated growth in Kindergarten enrollment over time, for each zoned school

4.     Public Supply, Total = PK4 slots currently available thru MNPS and Head Start, by cluster 

5.     Public Supply, EE = Public PK4 slots allocated exclusively for children receiving Exceptional Education services

6.     Private Supply = Slots currently provided by private entities, by cluster.

7.     Private "High-Quality" Supply = Slots that are provided by entities that are accredited by the National Association for the Education of Young Children (NAEYC), or that are three-star providers as determined by the voluntary Star-Quality Child Care Program (determined by the TN Department of Human Services Child Care Services office).

8.     Accessibility = Characteristic of each school zone's residents, which indicates families' reliance on public transportation vs. private vehicles (aggregated at the census tract level, using the ACS package in R - about which I have a blog post under construction).

Assumptions:  Every child who attends a MNPS elementary for kindergarten is likely to consider enrolling in a MNPS PK4 classroom if it were available in their residential cluster. Therefore, it is appropriate to consider projected Kindergarten enrollment in AY1415 as an appropriate proxy for projected PK4 need in AY1314. 

Limitations:    (1) Analysis captures anticipated trends for zoned schools, rather than trends for schools of choice or specialty schools. (2) Although it is intended to reflect the reality that some parents will always choose to keep their 4-year-old at home or choose private providers rather than enroll them in public PK4, the distinction between Need and Demand seems a little bit fussy, and ultimately may not be useful. (3) This is a preliminary working construct of "high quality" and cannot, by definition, capture all the characteristics that make up a quality ECE experience. But we must start somewhere, and so we start with NAEYC and Three-Star.

Thoughts, questions, suggestions? Did I miss something really obvious?