Indiana Small and Rural Schools Association Relevant Research on School Consolidation.

Dollars & Sense provides a review of all research on the educational and social benefits of small schools and its stakeholders in the community.  This paper reviews another perspective on the “diseconomies of scale” inherent in larger schools. The research documents measuring the cost of education by graduates rather than by all
students who go through the system suggests that small schools are a great investment for any taxpayer.  

https://www.ruraledu.org/user_uploads/file/Dollars_and_Sense.pdf 

Pennsylvania did a major study of school consolidation in their state and the nation.  The study provides an overall balanced review documenting the benefits and costs are situational based on the schools, population, demographics, and even geography.  

“While school district consolidation is often associated with anticipated cost savings and tax
reductions, it is a very complex process, involving multiple contributing factors, like changes in
state funding, additional expenses necessitated by salary equalization, and capital costs. A
California study cautions that, in addition to losing funding, which may be the case for some
Pennsylvania districts that choose to merge as well, “consolidating can lead to higher costs for
districts, both in the short term (such as the administrative costs of the consolidation process) and
longer term (such as the pressure to increase staff compensation to match that of the most generous
consolidating district.”  (School Districts in Pennsylvania Ways to Work Together, 2017, p.6).

“The focal point of this study is educational productivity. The researchers argue that “in
many ways, the real problem is not district size. The real problem is our nation’s system for
managing districts”; they strongly recommend a new approach to district governance: “we need to
better support more districts that generate higher-than-average achievement per dollar spent and
encourage efforts to study highly productive districts.”106 The conclusion is that “in the end, what’s
important is to provide districts with the supports and incentives to find better and more-effective
ways to spend their dollars.”  (School Districts in Pennsylvania Ways to Work Together, 2017, p.6).

JOINT STATE GOVERNMENT COMMISSION
General Assembly of the Commonwealth of Pennsylvania, SCHOOL DISTRICTS IN PENNSYLVANIA:
WAYS TO WORK TOGETHER, 2015 House Resolution 910 Staff Study July 2017

http://jsg.legis.state.pa.us/resources/documents/ftp/publications/2017-07-31%20Final%20Report%20HR910%207.31.17%20220pm.pdf

Illinois Center for Education Policy provided an insightful analysis on consolidation. 

Norm Durflinger, Ed.D., Lynne Haeffele, Ph.D.   Illinois Public School Consolidation A Tiered Approach. Center for the Study of Education Policy. Illinois State University. March 2011

Their study found:
The research on consolidation can be summarized as follows: Economies of scale are greatest when small districts merge; as districts get larger, at some point the economies plateau and then expenses rise with increasing district
complexity. Student performance is equal or better in small schools. Other considerations besides finances should be part of consolidation deliberations. (Durflinger and Haeffele, 2011, p.3.)

https://education.illinoisstate.edu/downloads/csep/IllinoisPublicSchoolDistrictConsolidation-ATieredApproach_FINALUSETHIS.pdf