Inequality
A recent study tested whether showing University of California employees where they could access a database with the salaries of their co-workers would change how they felt about their own job. It did, but it an asymmetric way. Workers discovering that they earned more than their peers experienced no gains in job satisfaction, while those discovering they earned less than their co-workers had a noticeable decline in job satisfaction and were more likely to indicate they’d be looking for a new job in the next year.
In K-12 education, teachers already know, or easily could find out, the salary of their co-worker down the hall.