Policy Matters Ohio has just released a report looking at the Benefits of Bargaining, titled "How Public Worker Negotiations Improve Ohio Communities". You can read the full report here (PDF).

We've pulled out the executive summary dealing with education.

Teachers: Teachers’ unions bargain to improve classroom conditions, benefitting teachers and students alike. Some of the issues teachers’ unions negotiate that improve student outcomes are:

Class size: Teachers’ unions often bargain to maintain low class sizes, especially in K-3 classes. Studies have shown that small classes are especially helpful to younger students, low-income students and students from minority communities. Small classes enable more writing assignments, better student-teacher relationships, and safer, more stable classroom atmospheres. We found that teacher unions often bargain to shrink and maintain class sizes, while management sometimes seeks to save money by increasing class sizes.
Discipline plans: Public employers and teachers’ unions use collective bargaining to develop discipline plans for students in order to minimize classroom disruptions. Under Senate Bill 5, discipline plans can be made without teacher input, which could undermine teacher authority and increase disruption. We also found examples of proactive union steps to prevent discipline problems. The Cleveland Teachers’ Union has negotiated to create In-School-Suspensions, to keep students off the streets and ensure discipline challenged students get proper treatment.
Improving school quality: Teacher unions fight for classes that improve curriculum. They have negotiated to ensure multiple choices of foreign language classes in high schools and to ensure music, art, and physical education classes in elementary schools. These classes also provide preparation periods for core-class teachers, which can improve their performance.
Improved Evaluations: Ohio teacher unions have been especially proactive in creating teacher evaluation and training systems. The Toledo Federation of Teachers created the Peer-Assistance and Review (PAR) program in the 1980’s, which pairs veteran teacher mentors with newly-hired or struggling teachers to provide guidance and evaluation. The PAR program is now in over 70 school districts around the country, including Toledo, Cleveland, Cincinnati, and Columbus, and has been praised as one of the best systems for improving new teacher quality.
Our contract and literature review also found seniority in layoffs is not well understood. Generally seniority is only used as a tie-breaker after other circumstances have been considered, and principals retain a large amount of discretion in hiring and layoffs.

Policy Matters Ohio reminds us of some of the provisions within SB5 that constitute the attack on collective bargaining

Senate Bill 5 was passed in March 2011. Key provisions of the bill include:

Eliminating the right to strike for all public workers;
Limiting the right to bargain over health insurance, pensions, staffing levels and working conditions;
Confining bargaining rights for state-level employees to wage issues only;
Eliminating binding arbitration, a process for resolving impasses for safety forces, described below;
Allowing the legislative body to impose its own resolution in the case of an impasse;
Reclassifying most professors as management to take them out of bargaining units;
New minimum requirements for employee contributions to health insurance and pensions;
Restricting the ability of teachers to advocate for more effective classroom practices, including smaller class sizes and better teacher evaluations.