In 2005 the UFT leadership under Randi Weingarten, irreversibly changed the dynamics of a school by agreeing to a contract that gave principals unlimited authority to run the schools as they saw fit. This post is not about how terrible the "giveback" laden contract was but about how principals used and abused their newly won power to do as they pleased and how it hurt student academic achievement.
Principals were given unfettered authority to hire and fire as they pleased. The result was that far too many schools hired newly minted teachers with little or no actual classroom experience and student academic achievement suffered as these "newbie" teachers had a steep learning curve themselves when it came to curriculum knowledge and classroom management issues. Some schools like Maspeth High School in Queens has an entire staff of untenured teachers. Moreover, many of the Bloomberg small schools have a majority of untenured teachers on staff.
The DOE policies encouraged principals to hire inexperienced teachers with their "fair student funding" that incentivized principals to "hire the cheapest and not the best teachers" for their schools. Moreover, approximately 25% o0f all principals came from the infamous "Leadership Academy" many of them with limited classroom experience and were trained to be the CEO and not the instructional leader of their school. Interestingly, where you find both Leadership Academy principals and an inexperienced teaching staff, student academic achievement suffers.
I once wrote the weakest link in the school system is the Superintendent. In New York City this is especially true as the superintendents seem to get their position based upon who they know ands not what they know. Just take a look at all the bad principals associated with Superintendent Juan Mendez, who has been indited by the feds for racial discrimination. Many of the "bad principals" in Queens high schools wee either appointed by or protected by Mr. Mendez. Again, student academic performance suffers as these "bad principals" experience high teacher turnover, an unstable school environment, and lack of collaboration.
The bottom line giving principals unlimited power only hurts student academic achievement.