Simulating Alternative School Choice Options in Boston-Main Report

Pathak, Parag A., and Peng Shi. (2013).

This report evaluates alternative school choice options for Boston Public Schools (BPS) using demand analysis based on historical data on families’ choices under the Boston student assignment plan. Using demand estimates, we evaluate the proposed alternative assignment plans by simulating how families would choose schools in these plans and how this interacts with the assignment algorithm. Our approach is to examine what would have happened in Round 1 of 2012-2013 had a new assignment plan been implemented in that year.

The aspects we analyze include:

• Equitable Access to Academic Quality (as measured by school MCAS)

• Access to Top Dream Choice

• Access to Top Menu Choice

• Bus Coverage Area

• Diversity (Socioeconomic and Racial)

• Community Cohesion (estimated # of same grade neighbors who can travel to school together)

The plans analyzed in this report include all of the original BPS plans (see BPS (2012)), a new BPS zone-based plan, and two non-zone based plans. The new zoned plan was developed by BPS and has 10 zones. The two non-zoned based plans, called Closest Types 1 and Closest Types 2, were developed by Peng Shi to replace the earlier Grouped School models. These two plans are based on the Closest Types concept: families are able to rank the closest schools, plus a certain number of closest top 25% MCAS schools, a certain number of closest top 50% MCAS schools, a certain number of top 75% MCAS schools, and a certain number of capacity schools. For the list of these school types, maps, examples, and full description, see the separate and independent write-up contained in Shi (2013). Closest Types 1 has choice menu size comparable to a 10-zone plan, while Closest Types 2 has choice menu size comparable to a 6-zone plan. In the future, these plans may change due to community feedback or other considerations. To avoid ambiguities, we precisely describe the versions analyzed in this report in Section 3.

For clarity of exposition, this report focuses on comparing the status quo with the three new plans. We report these plans based on guidance from BPS, who recommended this shortlist after seeing the preliminary results for all plans. The Graph appendix (Pathak and Shi 2013a) contains analysis of all of the original BPS plans. Detailed information on the simulation methodology is described in the Technical Appendix (Pathak and Shi 2013b).

The analysis shows that the selection of an assignment plan involves tradeoffs on a number of dimensions. Roughly speaking,

• A plan with a larger choice menu offers more equitable access, more access to top dream choice, and greater diversity; however, this comes at a cost of longer distance traveled, higher transportation costs, and lower levels of community cohesion.

• A plan with a smaller choice menu with options closer to home, decreases travel distance, lowers transportation costs, and improves community cohesion; but this may lower access to quality for some, decrease the access to dream choice, and decrease diversity.

• Zone-based plans have advantages of long-term predictability, ease of adaptation and description (since the current plan is zone-based), and time-proven implementability.

• Non-zone-based plans may more easily adapt to changes in school quality and demographics, but require care in implementation and explanation to ensure predictability.

The report is organized as follows. In Section 2, we outline our methodology at a high level. Additional details are in the Technical Appendix (Pathak and Shi 2013b). Section 3 provides a precise description of the plans analyzed. In Section 4, we describe the metrics we use to evaluate plans and define precisely how they are computed and what they represent. In Section 5, we summarize our findings and compare plans side-by-side using these metrics. Section 6 contains more details for the status quo and the new plans, including breakdowns by English Proficiency status, socioeconomic status, race, and neighborhood. In the last section, we report the effects of processing order changes and changing the walk-zone set aside percentage.

For clarity, in this report we focus on grade K2, and most of the statistics are shown for new families (non-continuing, non-sibling) because these are the primary population affected by assignment plan reform. (See the beginning of Section 5 for more discussion.) In all of the analysis, we assume the ELL overlay. For analysis of grade K1, additional graphs, and analysis of old BPS plans, see the Graph Appendix (Pathak and Shi 2013a).